Involuntary loss of urine that is objectively demonstrable and constitutes a social or hygienic problem.

Exam domain	One-glance essentials
Definition / diagnosis	*Urinary incontinence is involuntary urine leakage; common types are stress, urgency, mixed, overflow, and functional incontinence* ^[1]^[2] Correct classification is essential because treatments differ ^[1]
Epidemiology / risks	Risk factors include pregnancy and vaginal birth, age, obesity, menopause, pelvic surgery, neurological disease, diabetes, constipation, and chronic cough ^[1]^[2] Medications, mobility, cognition, and fluid habits can aggravate symptoms ^[1]
Core mechanism	Stress incontinence: raised abdominal pressure exceeds urethral closure; urgency incontinence: involuntary detrusor contraction ^[1]^[2] Overflow follows impaired emptying from obstruction or detrusor underactivity ^[1]
Clinical picture	*Stress leakage occurs with cough or exertion; urgency leakage follows a sudden compelling desire to void* ^[1]^[2] Continuous leakage suggests fistula; weak stream, incomplete emptying, or palpable bladder suggests retention or overflow ^[1]
Investigations	Use history, examination, cough stress test, urinalysis, bladder diary, and post-void residual when indicated ^[1]^[2] Urodynamics is selective before complex or invasive treatment, not mandatory for every straightforward case ^[1]
Management	First-line: pelvic-floor muscle training for stress or mixed incontinence; bladder training for urgency plus weight and fluid optimisation ^[1]^[2] Medicines treat urgency; surgery treats selected stress incontinence after counselling on benefits, alternatives, and mesh-related issues ^[1]
Complications	Complications include skin injury, recurrent UTI, falls, sleep disturbance, sexual dysfunction, depression, and social isolation ^[1]^[2] Chronic retention may cause hydronephrosis and renal impairment ^[1]
Prevention / follow-up	Pelvic-floor training around childbirth, healthy weight, constipation and cough treatment, and medication review reduce risk and burden ^[1]^[2] Review response and residual urine when treatment or symptoms suggest impaired emptying ^[1]
Exam traps	*Do not assume all leakage is stress incontinence* ^[1]^[2] A positive dipstick or bacteriuria does not explain chronic symptoms automatically; continuous leakage and high residual urine require different pathways ^[1]

References

^[1] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (female urinary incontinence) ^[2] Lecture slides: Block C - O&G Theme Case 4.pdf (incontinence classification and management)

Urinary Incontinence

Urinary incontinence (UI): the complaint of any involuntary leakage of urine ^[1]. This is the standardised IUGA/ICS (International Urogynecological Association / International Continence Society) definition from 2010 ^[1].

Let's break down the terminology:

"Urinary" = relating to urine (Latin: urina)
"Incontinence" = inability to contain (Latin: in- = not, continentia = holding together)

So the name literally tells you: the person cannot hold their urine in.

Key Distinction

UI is not the same as enuresis. Enuresis refers to any involuntary loss of urine (classically nocturnal bedwetting), while urinary incontinence specifically implies it is a social/hygienic problem that is objectively demonstrable ^[2]. In clinical practice, "incontinence" carries the connotation of a clinically significant complaint affecting quality of life.

Related terminology:

Nocturia: waking ≥ 1 time per night to void, with each void preceded and followed by sleep ^[2]
Overactive bladder (OAB): a clinical syndrome of urgency ± frequency ± nocturia ± urge incontinence, in the absence of UTI or other obvious pathology — subdivided into Dry OAB (urgency without leakage) vs Wet OAB (urgency with leakage, i.e. urge incontinence) ^[1]

Prevalence is highly variable because of differences in definition, method of enquiry, and the nature of the population studied ^[1]
General figures: affects approximately 1 in 4 women and 1 in 10 men, with prevalence increasing with age but NOT a normal part of ageing ^[2]
In women:
- Stress UI is the most common type in younger women (< 60 years)
- Mixed incontinence becomes more prevalent with age
- Urge UI predominates in older women (> 70 years)
In men:
- UI is less common than in women (the prostate acts as a continence device) ^[2]
- Post-prostatectomy stress UI is a significant cause
- Urge UI from OAB/BPH is common in older men
Hong Kong context: With an ageing population and high prevalence of diabetes mellitus, UI is a significant public health issue. Many patients under-report symptoms due to embarrassment or the misconception that it is a normal part of ageing.

Genital prolapse and incontinence are important primary health problems of women ^[3].

Although genital prolapse and urinary incontinence are not life-threatening conditions, they can affect the quality of life of a woman ^[3].

High Yield Exam Point

UI is NOT a normal part of ageing. Always look for a treatable cause. The prevalence increases with age due to accumulation of risk factors (pelvic floor weakening, comorbidities, medications), not because of ageing per se.

3. Risk Factors

Risk factors are best understood by thinking about what maintains continence and what can go wrong.

Risk Factor	Mechanism / Why
Vaginal childbirth / Multiparity ^[1]^[3]^[4]	Stretching and tearing of pelvic floor muscles (levator ani), pudendal nerve damage during delivery, fascial disruption — all weaken the support holding the urethra and bladder neck in place
Menopause ^[4]	Oestrogen deficiency → atrophy of urethral mucosa and periurethral tissues → reduced mucosal coaptation and submucosal vascular cushion → reduced intrinsic urethral closure pressure
Obesity / Raised BMI ^[4]^[5]	Chronically raised intra-abdominal pressure → stretches and weakens pelvic floor over time; also a risk factor for prolapse progression
Age ^[4]	Cumulative tissue degeneration, sarcopenia of pelvic floor muscles, reduced collagen quality
Chronic constipation ^[4]	Repeated straining → chronic raised intra-abdominal pressure → pelvic floor damage
Diabetes mellitus ^[4]	Autonomic neuropathy → detrusor underactivity → overflow incontinence; also peripheral neuropathy affecting pelvic floor innervation; diabetic polyuria worsens symptoms
Pelvic surgery / radiotherapy	Disruption of pelvic floor support, nerve damage
Grand multiparity ^[5]	More deliveries = more cumulative pelvic floor trauma

Risk Factor	Mechanism
Neurological disease (stroke, MS, PD, SCI, NPH)	Disruption of pontine micturition centre control → detrusor overactivity or detrusor-sphincter dyssynergia
Medications (see drug causes below)	Anticholinergics → retention → overflow; diuretics → polyuria; alpha-blockers → reduced sphincter tone
Cognitive impairment / dementia	Functional incontinence — inability to recognise urge or reach toilet
Impaired mobility	Functional incontinence
UTI	Bladder mucosal irritation → detrusor overactivity → transient urge incontinence
Smoking	Chronic cough → repetitive stress on pelvic floor
Caffeine / excessive fluid intake	Bladder irritant + polyuria

Risk Factor	Mechanism
Post-prostatectomy (radical or TURP)	Damage to external sphincter mechanism → stress UI (10% after RP) ^[6]
BPH	Detrusor overactivity secondary to chronic BOO → urge UI; or chronic retention → overflow UI

4. Anatomy and Function of the Continence Mechanism

Understanding incontinence requires understanding what keeps you continent. Think of it as a system with structural, muscular, neural, and mucosal components all working together.

The pelvic floor is more than just the levator ani muscles. More accurately, it includes all structures supporting the pelvic cavity: peritoneum, pelvic viscera, endopelvic fascia, levator ani, perineal membrane, and superficial genital muscles ^[3].

Key components:

Levator ani muscle complex (the most important muscular component):
- Comprises: pubococcygeus (including pubovaginalis in women), puborectalis, iliococcygeus
- Innervation: direct branches from S3–S4 (pudendal nerve branches and direct sacral branches)
- Function: provides a "hammock" of tonic contraction that supports pelvic organs and keeps the urogenital hiatus closed
- The pubovaginalis portion specifically forms a U-shaped sling around the vagina and urethra in women — when it contracts, it compresses the urethra against the pubic symphysis
Endopelvic fascia (connective tissue):
- Pubocervical fascia (anterior vaginal wall support → supports bladder)
- Rectovaginal fascia (posterior vaginal wall support → supports rectum)
- Cardinal and uterosacral ligaments (apical support)
- When this fascia weakens or tears, organs prolapse through the vaginal walls
Perineal membrane (urogenital diaphragm):
- A triangular fibromuscular sheet spanning the anterior pelvic outlet
- Supports the distal urethra and vagina
External urethral sphincter (rhabdosphincter):
- Striated muscle under voluntary (somatic) control
- Innervated by the pudendal nerve (S2–S4)
- Provides "guarding reflex" — reflexive contraction during sudden increases in abdominal pressure (cough, sneeze)

Physiologically, continence arises from ^[2]:

Anatomical support by intact pelvic floor holding bladder neck and urethra in place (especially in females) ^[2]
- The "hammock hypothesis" (DeLancey): the urethra rests on a hammock of supportive tissue (anterior vaginal wall + endopelvic fascia + levator ani). When abdominal pressure rises, the urethra is compressed against this hammock → maintains closure
- If the hammock is weak or lax (e.g. after vaginal delivery), the urethra descends and can no longer be compressed → stress incontinence
Intrinsic urethral mechanism by ^[2]:
- Coaptation of mucosa — the urethral mucosa folds inward to create a watertight seal (oestrogen-dependent in women — this is why menopause is a risk factor)
- Compression by submucosa and internal/external sphincters — the submucosal vascular plexus acts as a "cushion" that helps seal the urethra; the smooth muscle internal sphincter (sympathetic, α1-adrenergic tone) provides resting tone; the striated external sphincter provides voluntary and reflex closure
Prostate as a continence device in males → the above factors are less important ^[2]
- The prostate surrounds the proximal urethra and contributes to urethral resistance. This is why men have lower rates of stress incontinence — but it also explains why prostatectomy can cause stress UI.
Neurological control by CNS and spinal cord ^[2]

4.3 Neural Control of Micturition

This is absolutely critical to understand because different neurological lesions produce different types of incontinence.

Component	Nerve	Origin	Neurotransmitter	Effect
Parasympathetic (pelvic nerve)	Pelvic splanchnic nerves	S2–S4	ACh (muscarinic M3)	Detrusor contraction (voiding)
Sympathetic (hypogastric nerve)	Hypogastric nerve	T10–L2	Noradrenaline	β3 receptors on detrusor → relaxation (storage); α1 receptors on bladder neck/internal sphincter → contraction (storage)
Somatic (pudendal nerve)	Pudendal nerve	S2–S4 (Onuf's nucleus)	ACh (nicotinic)	External sphincter contraction (voluntary continence)
Central	—	Pontine micturition centre, cerebral cortex	—	Coordinates the switch between storage and voiding; provides conscious control

Lesion Location	Phase	Pattern	Result
Suprapontine (stroke, dementia, PD, NPH)	Loss of cortical inhibition on PMC	Detrusor overactivity with intact coordination	Urge incontinence (the bladder contracts involuntarily but sphincters still relax appropriately)
Suprasacral spinal cord (SCI above S2, MS)	Loss of PMC coordination	Detrusor-sphincter dyssynergia (DSD): simultaneous contraction of detrusor AND sphincters ^[2]^[7]	High-pressure voiding → upper tract damage, UTI, autonomic dysreflexia
Sacral cord / cauda equina (S2–S4 lesion)	Loss of detrusor motor innervation	Areflexic/hypotonic bladder	Overflow incontinence (constant dribbling, large residual)
Peripheral nerve (DM neuropathy)	Progressive denervation	Detrusor underactivity	Overflow incontinence

Why does suprasacral SCI cause DSD?

Normally, the PMC (Barrington's nucleus in the pons) acts as the "coordination centre" — when it commands the detrusor to contract, it simultaneously commands the external sphincter to relax. In suprasacral SCI, the spinal reflex arc is intact (so the detrusor can contract reflexively), but the PMC signal that tells the sphincter to relax is interrupted. The result: both contract at the same time → very high intravesical pressures → risk of vesicoureteral reflux → hydronephrosis → renal failure ^[2]^[7].

5. Aetiology and Pathophysiology

5.1 Classification of Urinary Incontinence by Type

Subtypes of urinary incontinence: Structural incontinence, Stress, Urge, Overflow, Functional, Mixed ^[3].

Definition (Clinical): Stress urinary incontinence — involuntary loss of urine on effort or physical exertion or on sneezing or coughing ^[1]

Definition (Urodynamic): Urodynamic stress incontinence — the finding of involuntary leakage during filling cystometry, associated with increased intra-abdominal pressure, in the absence of a detrusor contraction ^[1]

Clinical vs Urodynamic Diagnosis

The clinical symptom is called "stress urinary incontinence." The confirmed urodynamic diagnosis is called "urodynamic stress incontinence." They are not interchangeable — a woman who complains of stress incontinence may actually have detrusor overactivity on urodynamics. This is why urodynamics may be needed before surgery ^[1].

Pathophysiology — two mechanisms:

Urethral hypermobility (most common):
- Weakened pelvic floor → loss of anatomical support for the urethra and bladder neck ^[1]^[4]
- When abdominal pressure rises (cough, sneeze, Valsalva), the urethra is no longer compressed against the supportive "hammock" → intra-abdominal pressure exceeds urethral closure pressure → leakage
- Intra-abdominal pressure > urethral pressure ^[6]
- Risk factors: vaginal delivery, menopause, obesity, chronic straining
Intrinsic sphincter deficiency (ISD):
- The sphincter mechanism itself is deficient (weak muscular tone, poor mucosal coaptation)
- Causes: prior surgery (e.g. radical prostatectomy, anti-incontinence surgery), radiation, neurological disease, ageing
- Typically more severe — leaks with minimal provocation or even at rest

Triggers: cough, sneeze, laughing, heavy lifting, running, jumping — anything that raises intra-abdominal pressure ^[2]

Definition (Clinical): Urgency urinary incontinence — involuntary loss of urine associated with urgency ^[1]

Definition (Urodynamic): Detrusor overactivity — involuntary detrusor muscle contractions occur during filling cystometry ^[1]

Pathophysiology:

The detrusor muscle contracts involuntarily during the filling/storage phase, generating intravesical pressure that overcomes urethral resistance → leakage
Overactive bladder syndrome / detrusor hyperactivity causing increased intravesical pressure ^[6]

Aetiologies of detrusor overactivity:

Category	Examples	Mechanism
Neurogenic	Stroke, PD, MS, SCI, NPH, TBI	Loss of cortical inhibition on PMC → uninhibited detrusor contractions ^[7]
Non-neurogenic	Idiopathic (most common), secondary to BOO, bladder pathology (cystitis, tumour, stones, FB), drugs (cholinesterase inhibitors) ^[7]	Various: inflammation → afferent hypersensitivity; BOO → tissue ischaemia → denervation supersensitivity; idiopathic: possibly myogenic or neurogenic micro-changes
Infection	UTI	Mucosal inflammation → afferent hyperstimulation → reflex detrusor contractions ^[6]

Idiopathic detrusor overactivity is the most common cause and its exact pathophysiology remains incompletely understood ^[3].

BOO → OAB Connection

Up to 30-60% of patients with bladder outlet obstruction develop detrusor overactivity. The postulated mechanism: chronic obstruction → ↑ intravesical pressure → tissue ischaemia → smooth muscle injury and cholinergic denervation supersensitivity → spontaneous detrusor contractions ^[7]. This is why men with BPH often have both obstructive AND irritative LUTS.

Combination of both stress and urge incontinence
Often mixed with SUI (mixed incontinence) and may be worsened by anxiety/stress ^[2]
Very common in older women
Management targets the predominant, most bothersome component first

Definition: Constant dribbling (especially at night) with associated retention of urine ^[2]

Pathophysiology:

BOO / detrusor underactivity (DUA) → bladder over-distension with continuous dribbling ^[2]
The bladder fills beyond its capacity and "spills over" — urethral pressure is eventually exceeded by the sheer volume of urine
Chronic urinary retention ^[6]

Causes:

Obstruction: BPH (most common in men), urethral stricture, pelvic organ prolapse (in women — cystocele leads to difficulty in completely emptying bladder, kinked urethra ^[4]), faecal impaction
Underactive detrusor: DM neuropathy, cauda equina syndrome, post-anaesthetic, medications (anticholinergics, opioids), chronic overdistension injury

Signs: Significant post-void residual, palpable bladder ^[2]

Complications: UTI, bladder stones, obstructive uropathy ^[2]

Definition: Urine leakage due to inability to get to toilet ^[2]

Causes: Impaired mobility (e.g. elderly), dementia, lack of carer ^[2]

The lower urinary tract itself is often normal
Usually a diagnosis of exclusion as other types also present in functionally limited individuals ^[2]

Definition: Constant, unremitting leakage

Causes:

Anatomical abnormalities (e.g. ectopic ureter), bladder fistula — consider in female ^[6]
Vesicovaginal fistula (VVF): classically post-hysterectomy, post-radiation, or obstetric injury (prolonged obstructed labour — important in developing countries)
Ectopic ureter: drains below the sphincter mechanism (in girls — presents as continuous wetness since birth alongside normal voiding)
Urethral diverticulum

A useful mnemonic for transient causes is DIAPPERS (or DIAPERS):

Letter	Cause	Mechanism
D	Delirium	Acute confusion → patient unaware of bladder signals
I	Infection (UTI)	Mucosal irritation → urgency and frequency → urge incontinence
A	Atrophic urethritis/vaginitis	Oestrogen deficiency → mucosal thinning → reduced urethral coaptation
P	Pharmaceuticals	See drug causes below
P	Psychological (depression)	Apathy → reduced motivation to reach toilet
E	Excess urine output (polyuria)	DM, DI, excessive fluid/caffeine intake, diuretics → overwhelms bladder capacity
R	Restricted mobility	Cannot reach toilet in time → functional incontinence
S	Stool impaction (constipation)	Faecal mass compresses bladder neck/urethra → overflow; also stimulates detrusor overactivity via shared sacral afferents

Drug Class	Mechanism	Type of UI
Diuretics (furosemide, HCTZ)	Polyuria → overwhelms bladder capacity	Urge / functional
Anticholinergics (TCAs, antihistamines, antipsychotics)	Detrusor underactivity → retention → overflow	Overflow
Alpha-blockers (prazosin, tamsulosin)	Relax internal sphincter tone → reduced urethral resistance	Stress (esp. in women)
Alpha-agonists (pseudoephedrine)	↑ urethral tone → retention	Overflow
Calcium channel blockers	Detrusor relaxation → impaired emptying	Overflow
Opioids	↓ detrusor contraction + ↓ sensation	Overflow
Cholinesterase inhibitors (donepezil)	↑ ACh → detrusor overactivity	Urge ^[6]
Sedatives/hypnotics	↓ awareness → functional	Functional
ACE inhibitors	Chronic cough → repeated pelvic floor stress	Stress (worsening)

6. Classification

Type	Mechanism	Typical Patient	Key Feature
Stress (SUI)	Urethral hypermobility / ISD	Younger multiparous women	Leaks with cough/sneeze; no urgency
Urge (UUI)	Detrusor overactivity	Older women; men with BPH/neuro	Sudden urgency → can't make it to toilet
Mixed	Both SUI + UUI	Older women	Features of both
Overflow	BOO or DUA	Men with BPH; DM neuropathy	Constant dribbling; palpable bladder
Functional	Physical/cognitive barriers	Elderly, demented, immobile	Normal LUT but can't reach toilet
Continuous / Structural	Fistula, ectopic ureter	Post-surgical women; congenital	Constant wetness; never dry

Transient: reversible causes (DIAPPERS) — always look for these first!
Established / Chronic: structural or neurological cause requiring specific management

7. Clinical Features

History-Taking Framework:

Characterise the incontinence:

Timing: Does leakage occur with exertion (SUI), with urgency (UUI), continuously (fistula/overflow), or only at night (overflow/enuresis)?
Triggers: Cough, sneeze, laughing, exercise (SUI); running water, key-in-lock (UUI — conditioned reflex triggers)
Volume: Small spurts (SUI); large volume gush (UUI); constant dribble (overflow)
Associated symptoms: Urgency, frequency, nocturia (OAB); hesitancy, weak stream, incomplete emptying (BOO → overflow); mass/lump at introitus (prolapse)

Symptom	Pathophysiological Basis	Suggests
Leakage with cough/sneeze/exertion	Raised intra-abdominal pressure exceeds weakened urethral closure pressure	SUI
Sudden urgency with inability to defer voiding	Involuntary detrusor contraction generates intravesical pressure exceeding urethral resistance	UUI
Frequency (> 8 voids/day)	Detrusor overactivity → reduced functional bladder capacity; or polyuria	OAB / UUI
Nocturia (≥ 1 void/night)	Nocturnal polyuria, OAB, reduced bladder capacity, sleep disturbance	Multiple causes
Constant dribbling	Bladder chronically overdistended → intravesical pressure exceeds urethral pressure continuously	Overflow
Hesitancy, weak stream, incomplete emptying	BOO or detrusor underactivity → voiding phase dysfunction	Overflow (underlying retention)
Continuous wetness (never dry)	Urine bypasses sphincter mechanism entirely via fistula or ectopic ureter	Structural/continuous
Feeling of "lump below" / mass at introitus ^[4]	Pelvic organ prolapse (cystocele, uterine prolapse) due to pelvic floor weakness — may co-exist with SUI	Prolapse ± SUI
Worsened by anxiety/stress	Central nervous system modulation of detrusor activity; psychological stress can lower threshold for detrusor contraction	UUI/Mixed

Always ask about:

Obstetric history: parity, mode of delivery, birth weight, instrumental deliveries, perineal tears
Menopausal status: oestrogen deficiency worsens SUI
Bowel habits: constipation both a risk factor and reversible cause
Medications: review full drug list (DIAPPERS)
Neurological symptoms: back pain, leg weakness/numbness (cauda equina), tremor (PD), previous stroke
Impact on quality of life: use of pads, social restriction, sexual dysfunction
Fluid intake: volume, type (caffeine, alcohol)
Bladder diary: urine output, voiding pattern, fluid intake pattern ^[6]

7.2 Signs (with pathophysiological basis)

Sign	Pathophysiological Basis	Significance
Obesity	Chronically raised intra-abdominal pressure → pelvic floor strain	Risk factor for SUI and prolapse
Cognitive impairment	Unable to recognise/respond to bladder signals	Functional incontinence
Impaired mobility	Cannot reach toilet in time	Functional incontinence
Peripheral neuropathy signs (glove-and-stocking sensory loss)	DM neuropathy → detrusor underactivity	Overflow incontinence

Sign	Pathophysiological Basis	Significance
Palpable bladder (suprapubic distension) ^[2]^[4]	Chronic urinary retention → overdistension	Overflow incontinence; bladder was full and palpable in the suprapubic region ^[4]
Abdominal mass	Pelvic tumour compressing bladder/urethra	Overflow / obstruction

Sign	Pathophysiological Basis	Significance
Urine leakage on straining (cough stress test) ^[4]	Raised abdominal pressure exceeds urethral resistance → demonstrates SUI	Confirms stress incontinence clinically
Cystocele (anterior vaginal wall descent) ^[4]	Defect in pubocervical fascia → bladder herniates into vaginal canal	May cause voiding difficulty (kinked urethra) → retention; associated with SUI
Rectocele (posterior vaginal wall descent)	Defect in rectovaginal fascia → rectum herniates into vagina	May cause incomplete defecation; associated with chronic straining
Uterine prolapse / cervical descent	Weakened cardinal/uterosacral ligaments → uterus descends	Cervix descended to 1cm beyond the introitus ^[4]
Vaginal atrophy	Oestrogen deficiency → thin, pale, dry vaginal mucosa	Reduced mucosal coaptation → worsens SUI
Urethral hypermobility (Q-tip test)	Weakened urethral support → excessive movement of urethra with straining	SUI due to hypermobility

Occult Stress Incontinence

Remember the possibility of occult stress incontinence in case of severe prolapse ^[1]. In severe pelvic organ prolapse, the prolapsed tissue may kink the urethra and actually mask stress incontinence. The patient appears continent only because the urethra is mechanically obstructed. When the prolapse is reduced (e.g. with a pessary or during surgery), the stress incontinence becomes apparent. This MUST be tested for before prolapse surgery — otherwise the patient will be "cured" of her prolapse but develop new-onset incontinence postoperatively.

Sign	Significance
Enlarged prostate (in males)	BPH → BOO → overflow/urge incontinence
Reduced anal tone	Suggests sacral nerve lesion (S2-S4) → neurogenic bladder
Faecal impaction	Reversible cause of incontinence (DIAPPERS — "S" for stool)
Rectal mass	Possible compression of bladder/urethra

Sign	Significance
Perianal sensation (S2-S4 dermatomes)	Tests sacral nerve integrity — absent in cauda equina syndrome
Bulbocavernosus reflex	Tests S2-S4 arc — absent in lower motor neuron lesion
Anal tone	Reduced in cauda equina / conus medullaris lesion
Lower limb neurology (power, reflexes, sensation)	Upper motor neuron signs suggest suprasacral cord lesion; lower motor neuron signs suggest cauda equina

Weakened pelvic floor support is the basic pathophysiology for both genital prolapse and stress urinary incontinence ^[1].

Common association of prolapse and urinary incontinence in an elderly woman ^[1].

Vaginal childbirth is an important risk factor for both conditions ^[1].

The relationship is nuanced:

Mild-moderate prolapse (especially cystocele) often co-exists with SUI because both share the same pathophysiology (pelvic floor weakness)
Severe prolapse may paradoxically mask SUI by kinking the urethra (occult stress incontinence)
If surgery is indicated, surgery for both conditions may be needed ^[1]
Conservative management is available but rarely curative ^[1]

Natural history of pelvic organ prolapse: prolapse waxes and wanes over time in individual women. Increasing BMI and grand multiparity increased the risk for vaginal descent progression ^[5].

Ageing population: Hong Kong has one of the world's oldest populations → increasing prevalence of UI
High prevalence of DM: autonomic neuropathy → overflow incontinence; also diabetic polyuria
Cultural factors: Many Chinese women are reluctant to discuss incontinence or undergo vaginal examination → under-reporting and delayed presentation
Occupational factors: Physically demanding occupations with heavy lifting may exacerbate SUI
Healthcare system: HA (Hospital Authority) provides subsidised urodynamic studies and continence services; awareness campaigns are important for early presentation

High Yield Summary

Definition: UI = complaint of any involuntary leakage of urine (IUGA/ICS 2010)

Epidemiology: 1 in 4 women, 1 in 10 men; increases with age but is NOT normal ageing

Key Risk Factors (Females): Vaginal childbirth, menopause, obesity, age, chronic constipation, DM

Continence depends on: (1) Pelvic floor support (hammock), (2) Intrinsic urethral mechanism (mucosal coaptation + sphincters), (3) Prostate in males, (4) Neurological control (cortex → PMC → sacral cord)

Types: Stress (exertional leakage, pelvic floor weakness), Urge (detrusor overactivity, sudden urgency), Overflow (retention → dribbling, BOO/DUA), Functional (mobility/cognition), Mixed, Continuous (fistula/ectopic ureter)

Clinical vs Urodynamic diagnosis: Stress UI ≠ Urodynamic stress incontinence; OAB ≠ Detrusor overactivity — urodynamics confirms the diagnosis

Neurological patterns: Suprapontine → urge UI; Suprasacral SCI → DSD (dangerous — high pressures → upper tract damage); Sacral/peripheral → overflow

Always look for reversible causes (DIAPPERS): Delirium, Infection, Atrophic urethritis, Pharmaceuticals, Psychological, Excess output, Restricted mobility, Stool impaction

Prolapse + SUI: Both share weakened pelvic floor pathophysiology. Severe prolapse may mask occult stress incontinence. If surgery needed, may need combined procedure.

Key lecture points: Weakened pelvic floor = basic pathophysiology for both prolapse and SUI. Vaginal childbirth = important risk factor. Remember occult stress incontinence in severe prolapse. Conservative Mx available but rarely curative.

Active Recall - Urinary Incontinence

^[1] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p51, p53, p74); Block C - I felt a lump below_ urinary incontinence in females; genital prolapse.pdf (p42, p45, p65) ^[2] Senior notes: Ryan Ho Urogenital.pdf (p159) ^[3] Lecture slides: Block C - I felt a lump below_ urinary incontinence in females; genital prolapse.pdf (p1, p45); Block C - O&G Theme Case 4.pdf (p1) ^[4] Lecture slides: Block C - O&G Theme Case 4.pdf (p4) ^[5] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p37) ^[6] Senior notes: Maksim Surgery Notes.pdf (p309, p316, p320) ^[7] Senior notes: Ryan Ho Fundamentals.pdf (p349, p354, p355); Ryan Ho Neurology.pdf (p53)

Differential Diagnosis of Urinary Incontinence

The differential diagnosis of urinary incontinence is really a two-layered problem. First, you must determine what type of incontinence the patient has (stress, urge, overflow, functional, continuous, or mixed). Second, you must determine what is causing that type. A third — and often forgotten — layer is to always consider whether the incontinence is transient (reversible) before labelling it as established.

Let me walk you through this systematically, the way you'd think on a ward round.

Before diving into anatomical and urodynamic subtypes, always screen for reversible causes first. This is crucial because treating the reversible cause can cure the incontinence without any further workup.

Use the mnemonic DIAPPERS (covered in Part 1, reused here for the DDx framework):

Transient Cause	Why It Causes Incontinence	How to Identify
Delirium	Acute confusion → patient cannot process bladder signals or respond appropriately	Acute onset, fluctuating cognition, identifiable precipitant
Infection (UTI)	Mucosal inflammation → afferent hyperstimulation → reflex detrusor contractions → urge UI	Dysuria, frequency, cloudy/offensive urine, +ve urine C/ST
Atrophic urethritis/vaginitis	Oestrogen deficiency → thinned urethral mucosa → loss of mucosal coaptation → reduced urethral closure pressure	Post-menopausal woman, vaginal dryness, pale atrophic mucosa on speculum
Pharmaceuticals	Multiple mechanisms (see drug table in Part 1)	Temporal correlation with drug initiation/dose change
Psychological (depression)	Apathy, reduced motivation to reach toilet	Screening for depression (PHQ-9)
Excess urine output	Polyuria overwhelms functional bladder capacity → frequency and urgency → leakage	Bladder diary showing high 24h urine volume (> 2.5-3L); check glucose, calcium, fluid intake
Restricted mobility	Cannot reach toilet in time despite intact LUT function	Observe mobility; check for arthritis, fractures, restraints
Stool impaction	Faecal mass in rectum → (1) mechanical compression of bladder neck, (2) shared sacral afferent stimulation → detrusor overactivity	DRE reveals loaded rectum; constipation history

Exam Tip

A very common mistake is to jump straight to urodynamics and surgery when a patient presents with new-onset incontinence. Always rule out transient causes first — especially UTI, medications, constipation, and delirium in the elderly. Treat these and reassess before any invasive investigation.

Once you have excluded or addressed transient causes and the incontinence persists, the next step is to differentiate between the established types. This is fundamentally a clinical exercise — the history is the most powerful tool.

Key Differentiating Features

Feature	Stress UI	Urge UI	Overflow	Functional	Continuous
Leakage trigger	Physical exertion, cough, sneeze, laugh	Sudden urgency (may be provoked by running water, cold, key-in-lock)	No clear trigger; positional changes; often at night	Inability to reach toilet	Constant, no relation to triggers
Volume leaked	Small spurts	Moderate-large gush	Constant small dribble	Variable	Constant
Urgency	Absent	Strong desire to void that is difficult to defer ^[2]	May be absent (bladder sensation impaired)	Present but patient cannot act on it	Absent
Voiding symptoms	Usually absent	May have frequency, nocturia	Hesitancy, weak stream, incomplete emptying, straining ^[6]^[7]	Usually absent	Usually absent
Post-void residual	Low (< 50 mL)	Low	Significant post-void residual, palpable bladder ^[2]	Low	Variable
Typical patient	Multiparous woman; post-prostatectomy male	Elderly woman; BPH male with OAB; neurological disease	BPH male; DM neuropathy; cauda equina	Demented/immobile elderly	Post-surgical female (fistula); congenital (ectopic ureter)

Clinical vs Urodynamic terminology ^[1]:

Stress urinary incontinence (clinical) → Urodynamic stress incontinence (urodynamic finding)
Overactive bladder / Urgency urinary incontinence (clinical) → Detrusor overactivity (urodynamic finding)
OAB can be Dry OAB (urgency without leakage) vs Wet OAB (urgency with leakage) ^[1]

This distinction matters because the clinical symptom does not always match the urodynamic diagnosis — up to 30% of women with clinically diagnosed stress UI will have detrusor overactivity on urodynamics, and vice versa ^[1].

3. Differential Diagnosis by Type — Underlying Aetiologies

Now, for each type of incontinence, you need to think about what is causing it. This is where you link the symptom pattern to a specific pathology.

Category	Specific Cause	Why It Causes SUI
Pelvic floor weakness	Vaginal childbirth / multiparity ^[4]	Stretching/tearing of levator ani + pudendal nerve damage → loss of urethral hammock support
	Menopause / oestrogen deficiency ^[4]	Atrophy of urethral mucosa → reduced mucosal coaptation
	Obesity ^[4]	Chronic raised intra-abdominal pressure → cumulative pelvic floor fatigue
	Chronic cough (e.g. COPD) ^[3]	Repetitive stress on pelvic floor
	Chronic constipation ^[4]	Repetitive straining
	Congenital collagen disorders (e.g. Ehlers-Danlos, Marfan)	Inherent weakness of connective tissue supporting urethra
Intrinsic sphincter deficiency	Post-radical prostatectomy ^[6]	Surgical damage to external urethral sphincter (late complication: stress UI in ~10%)
	Post-TURP ^[6]	Sphincter damage (rare, ~1%)
	Post-incontinence surgery ^[7]	Over-correction or scarring → may paradoxically worsen UI
	Radiation therapy	Fibrosis and devascularisation of sphincter mechanism
	Neurological disease (pudendal neuropathy)	Denervation of external sphincter

Weakened pelvic floor will contribute to stress urinary incontinence ^[4].

Category	Specific Cause	Why It Causes UUI
Neurogenic detrusor overactivity	Stroke, TBI	Loss of cortical inhibition on pontine micturition centre → uninhibited detrusor contractions ^[7]^[8]
	Multiple sclerosis	Demyelination of suprasacral spinal cord pathways → interrupted coordination
	Parkinson's disease	Degeneration of basal ganglia inhibitory pathways on micturition reflex
	Normal pressure hydrocephalus ^[9]	Stretching of periventricular fibres controlling bladder → classical triad: frontal dementia, apraxic gait, urinary incontinence ^[9]
	Spinal cord injury (suprasacral)	Initially spinal shock (retention) → then reflex detrusor overactivity ± detrusor-sphincter dyssynergia ^[8]^[10]
Non-neurogenic detrusor overactivity	Idiopathic (most common)	Unknown — possibly myogenic or microscopic neurogenic changes
	Secondary to BOO (e.g. BPH)	Chronic obstruction → tissue ischaemia → denervation supersensitivity → spontaneous detrusor contractions (affects 30-60% of BOO patients) ^[7]
	Bladder pathology: cystitis, tumour, stones, foreign body ^[7]	Local mucosal irritation → afferent hyperstimulation → reflex detrusor overactivity
	Drugs (cholinesterase inhibitors) ^[6]	↑ ACh at muscarinic M3 receptors on detrusor → enhanced contractility
	Drugs (diuretics)	Rapid bladder filling → overwhelms capacity → urgency

Think of this as two mechanisms: either the outlet is blocked or the muscle can't squeeze.

Mechanism	Specific Cause	Why
Bladder outlet obstruction (BOO)	BPH (most common in males, 53% of AROU) ^[11]	Static (stromal hyperplasia) + dynamic (smooth muscle contraction) components obstruct urethra
	CA prostate ^[11]	Tumour invasion/compression of urethra
	Urethral stricture ^[11]	Scarring narrows urethral lumen
	Cystocele / pelvic organ prolapse ^[3]^[4]	Prolapse of the bladder leads to difficulty in completely emptying bladder, kinked urethra ^[4]
	Faecal impaction	Extrinsic compression of bladder neck/urethra
	Gynaecological tumours (e.g. fibroid) ^[11]	Extrinsic compression
	Bladder/urethral stone ^[11]	Mechanical luminal obstruction
	Phimosis ^[11]	Tight foreskin → obstructed urethral meatus
Detrusor underactivity (DUA)	DM neuropathy ^[3]^[4]	Autonomic neuropathy → progressive denervation of detrusor → hypotonic bladder → ↓ability to sense full bladder, incomplete emptying
	Cauda equina syndrome ^[10]	Destruction of S2-S4 motor neurons → areflexic detrusor → autonomic: urinary retention with overflow incontinence, faecal incontinence, impotence ^[10]
	Conus medullaris lesion ^[10]	Similar — S2-S4 segment involvement
	Drugs: anticholinergics, opioids, alpha-agonists	Block detrusor contraction or increase outlet resistance
	Acute overdistension (post-GA, post-operative) ^[11]	Stretches detrusor beyond optimal length for contraction → ineffective voiding

Cause	Why
Dementia (Alzheimer's, vascular)	Cannot recognise bladder signals or navigate to toilet
Impaired mobility (arthritis, stroke, fracture)	Cannot reach toilet in time
Environmental barriers	Distant or inaccessible toilet, restraints, unfamiliar environment (hospitalisation)
Lack of carer	No assistance for toileting
Severe depression	Apathy → does not attempt to reach toilet

Cause	Why
Vesicovaginal fistula ^[6]	Abnormal connection between bladder and vagina → urine bypasses sphincter entirely; causes: post-hysterectomy (most common in developed countries), post-radiation, obstetric (developing countries)
Ureterovaginal fistula	Urine drains from ureter directly into vagina (classically post-pelvic surgery)
Ectopic ureter ^[6]	Ureter inserts below the sphincter mechanism → continuous leakage from birth (in girls); in boys, ectopic ureter always inserts above the sphincter so this doesn't cause incontinence
Urethral diverticulum	Pooling of urine in diverticulum → post-void dribbling / leakage
Severe intrinsic sphincter deficiency	Sphincter so weak that closure pressure is essentially zero

Why does ectopic ureter cause incontinence in girls but not boys?

In males, the ectopic ureter can insert into the prostatic urethra, seminal vesicle, or vas deferens — all of which are above the external sphincter. So the sphincter still guards against leakage. In females, the ectopic ureter can insert into the vagina, vestibule, or distal urethra — all below the sphincter mechanism. Urine therefore bypasses the sphincter entirely, causing continuous leakage.

4. Special Differential Diagnostic Scenarios

This is a classic exam scenario (as in the theme case ^[3]^[4]):

Internal organ prolapse, resulting in AROU → classify based on compartment of vagina that is weakened ^[3]:

Anterior → cystourethrocele
Middle → uterine / vault prolapse
Posterior → rectocele

The differential in this patient includes:

Stress UI from weakened pelvic floor (most common associated UI type)
Overflow incontinence from urethral kinking by the cystocele → need reduction of uterus before urination → or else it will kink the urethra, cannot urinate ^[3]
Urge UI from detrusor overactivity (can coexist)
Mixed incontinence (stress + urge — very common in this demographic)

Remember the possibility of occult stress incontinence in case of severe prolapse ^[1] — this is a key DDx consideration before any surgical planning.

Not ALL LUTS is due to BPH! → ≥ 1/3 of men with LUTS do NOT have BOO ^[7]

The differential includes:

BPH → BOO → overflow UI and/or secondary detrusor overactivity → urge UI ^[6]^[7]
CA prostate → BOO
Urethral stricture → BOO
OAB (idiopathic or neurogenic) → urge UI
Neurological disease (stroke, PD, MS, NPH) → urge UI
Post-prostatectomy → stress UI ^[6]

This is a favourite exam topic. The pattern of incontinence tells you the level of the lesion:

Level of Lesion	Examples	Bladder Pattern	Type of UI
Suprapontine (above pons)	Stroke, dementia, PD, NPH, brain tumour	Detrusor overactivity with coordinated sphincter relaxation	Urge UI
Suprasacral spinal cord (between pons and S2)	MS, SCI, transverse myelitis	Detrusor-sphincter dyssynergia (DSD) ^[2]^[8] — simultaneous detrusor contraction + sphincter contraction	Urge UI + high-pressure voiding → upper tract damage
Sacral cord / Conus (S2-S4)	Conus medullaris lesion, tumour	Areflexic detrusor (LMN bladder)	Overflow UI
Cauda equina	Disc herniation (L4/5, L5/S1), tumour, infection	Areflexic detrusor (LMN bladder); urinary retention with overflow incontinence, faecal incontinence, impotence ^[10]	Overflow UI
Peripheral nerve	DM neuropathy	Progressive detrusor underactivity	Overflow UI

Note that urinary incontinence may not always be due to sacral cord injuries. In suprasacral spinal cord injury, this reflex is absent in the spinal shock phase (AROU/overflow incontinence) and becomes hyperactive afterwards (urge incontinence) with reflexive bladder function (no voluntary control) or even detrusor striated sphincter dyssynergia (DESD) leading to reflux nephropathy. The pattern is all along hyporeflexic in sacral cord or nerve root injuries. ^[8]

Red Flag: Cauda Equina Syndrome

Cauda equina syndrome is the most important red flag to rule out in any patient with new-onset urinary retention/overflow incontinence + back pain ^[10]. Look for: bilateral radicular pain, saddle anaesthesia, reduced anal tone, absent bulbocavernosus reflex, lower limb LMN signs. This requires emergency MRI whole spine and surgical decompression within 48 hours — delay leads to irreversible sphincter dysfunction and incontinence ^[10].

The following algorithm represents the clinical approach to differentiating the type and cause of urinary incontinence:

Type of UI	Most Common Causes	Less Common / Must-Not-Miss Causes
Stress	Pelvic floor weakness (multiparity, menopause, obesity), chronic cough, constipation	ISD (post-prostatectomy, post-radiation), congenital connective tissue disorder
Urge	Idiopathic OAB, UTI, BPH-related OAB	Neurological (stroke, MS, PD, NPH, SCI), bladder tumour, bladder stone
Overflow	BPH (males), DM neuropathy, drugs (anticholinergics)	Cauda equina syndrome, urethral stricture, pelvic organ prolapse (females)
Functional	Dementia, immobility, hospitalisation	Depression, environmental barriers
Continuous	Vesicovaginal fistula (post-hysterectomy/obstetric)	Ectopic ureter (congenital), severe ISD
Mixed	Combination of stress + urge (very common in elderly women)	Any combination of the above
Transient	UTI, medications, constipation, delirium	Atrophic vaginitis, depression, excess fluid intake

These are the "clinical pointers" that help you narrow the DDx efficiently:

Historical Clue	Points Towards
Frequency > 7 voids in daytime, urgency, nocturia, urgency urinary incontinence ^[1]	OAB / Urge UI
Leakage only with cough/sneeze/exertion, no urgency	Stress UI
Progressive difficulty voiding + dribbling in a male > 50	BPH → overflow
DM → innervation to pelvic floor impaired ^[3]	Overflow UI (autonomic neuropathy)
COPD → chronic cough, increased abdominal pressure ^[3]	Stress UI (worsened)
Needs reduction of mass before urination ^[3]	Prolapse with urethral kinking → overflow
New back pain + saddle numbness + bilateral leg weakness	Cauda equina → overflow UI (EMERGENCY)
Gait disturbance + cognitive decline + incontinence	NPH (Hakim triad)
Continuous wetness since childhood with normal voiding	Ectopic ureter
Continuous wetness after pelvic surgery/difficult delivery	Vesicovaginal fistula
Acute confusion + new incontinence in hospital	Delirium (transient cause)
Incontinence started after new medication	Drug-induced (check which drug — see table)
Splinting required before defecation ^[3]	Rectocele → posterior compartment prolapse

The NPH Triad — A Classic DDx

Normal pressure hydrocephalus presents with the triad of frontal dementia, apraxic gait, and urinary incontinence ^[9]. The gait disturbance typically comes first ("magnetic gait" — feet appear glued to the floor), followed by cognitive decline, and incontinence comes last. This is important because NPH is one of the reversible causes of dementia — ventriculoperitoneal shunting can improve all three symptoms if caught early. On imaging, ALL ventricles are enlarged disproportionate to sulcal effacement ^[9].

Key DDx Principles to Remember:

Always screen for transient causes (DIAPPERS) before labelling incontinence as established

The history is the most powerful differentiating tool — characterise timing, triggers, volume, and associated symptoms

Clinical diagnosis does NOT always match urodynamic diagnosis — up to 30% discordance

Mixed incontinence is extremely common in elderly women — don't force a single diagnosis

Always think about neurological causes and perform a focused neuro exam (especially cauda equina — a surgical emergency)

In women with prolapse, always assess for occult stress incontinence

In men, not all LUTS = BPH — at least 1/3 of men with LUTS do not have BOO

High Yield Summary

DDx Framework: (1) Rule out transient causes (DIAPPERS), (2) Characterise type by history, (3) Identify underlying aetiology

Stress UI causes: Pelvic floor weakness (childbirth, menopause, obesity, cough, constipation), ISD (post-surgery, radiation, neuro)

Urge UI causes: Idiopathic OAB (most common), neurogenic (stroke, PD, MS, NPH, SCI), bladder pathology (UTI, stones, tumour), BOO-related, drugs

Overflow UI causes: BOO (BPH, stricture, prolapse) or DUA (DM neuropathy, cauda equina, drugs, post-GA overdistension)

Functional: Dementia, immobility, environmental. Continuous: Fistula (VVF), ectopic ureter

Neurological DDx by level: Suprapontine → urge; Suprasacral cord → DSD; Sacral/cauda equina → overflow

Red flags: Cauda equina syndrome (back pain + saddle anaesthesia + retention → emergency MRI + decompression < 48h); NPH (gait + dementia + incontinence → reversible with VP shunt)

Key lecture points: Clinical vs urodynamic diagnosis distinction is critical. OAB = Dry vs Wet. Not all LUTS = BPH. Prolapse can mask occult SUI. DM impairs pelvic floor innervation. COPD increases abdominal pressure.

Active Recall - Differential Diagnosis of Urinary Incontinence

References

^[1] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p53, p57) ^[2] Senior notes: Ryan Ho Urogenital.pdf (p159, p160) ^[3] Lecture slides: Block C - O&G Theme Case 4.pdf (p2, p4, p6) ^[4] Lecture slides: Block C - O&G Theme Case 4.pdf (p4) ^[6] Senior notes: Maksim Surgery Notes.pdf (p309, p316, p320) ^[7] Senior notes: Ryan Ho Fundamentals.pdf (p355) ^[8] Senior notes: Ryan Ho Neurology.pdf (p53) ^[9] Senior notes: Ryan Ho Psychiatry.pdf (p82) ^[10] Senior notes: Maksim Surgery Notes.pdf (p223); Maksim Medicine Notes.pdf (p47) ^[11] Senior notes: Ryan Ho Fundamentals.pdf (p349); Ryan Ho Urogenital.pdf (p164)

Diagnostic Criteria, Algorithm, and Investigations for Urinary Incontinence

Here's the key concept to grasp: urinary incontinence is primarily a clinical diagnosis made by history, but the specific subtype and underlying cause often require confirmation by investigations — especially before surgical intervention. The clinical diagnosis and the urodynamic diagnosis are not always the same thing, and this distinction is exam-critical.

1. Diagnostic Criteria

Unlike many medical conditions, urinary incontinence does not have a single set of "diagnostic criteria" like the Jones criteria for rheumatic fever. Instead, diagnosis proceeds in layers: (1) confirm incontinence exists, (2) classify the type, (3) identify the cause.

The IUGA/ICS definitions (Haylen 2010) ^[1] establish the clinical diagnostic terminology:

Clinical Diagnosis	Criteria
Stress urinary incontinence	Involuntary loss of urine on effort or physical exertion or on sneezing or coughing ^[1]
Urgency urinary incontinence	Involuntary loss of urine associated with urgency ^[1]
Overactive bladder (OAB)	Urgency ± frequency ± nocturia ± urge incontinence, in the absence of UTI or other obvious pathology; subdivided into Dry OAB vs Wet OAB ^[1]
Mixed urinary incontinence	Both stress and urgency components present
Overflow incontinence	Constant dribbling with significant post-void residual / palpable bladder ^[2]
Functional incontinence	Leakage due to inability to reach toilet; diagnosis of exclusion ^[2]
Continuous incontinence	Constant leakage (never dry) — think fistula or ectopic ureter ^[6]

Clinical vs Urodynamic: Why Both Exist

The clinical diagnosis is what the patient tells you. The urodynamic diagnosis is what the machine tells you. They do not always match — up to 30% discordance. A woman saying "I leak when I cough" might actually have detrusor overactivity provoked by coughing (not true stress UI). This is why urodynamics is recommended before surgical intervention — you want to be sure you are operating on the right diagnosis ^[1]^[7].

Urodynamic Diagnosis	Criteria
Urodynamic stress incontinence (USI)	The finding of involuntary leakage during filling cystometry, associated with increased intra-abdominal pressure, in the absence of a detrusor contraction ^[1]
Detrusor overactivity (DO)	Involuntary detrusor muscle contractions occur during filling cystometry ^[1] — i.e. a rise in detrusor pressure (Pdet) during the filling phase that the patient cannot suppress
Bladder outlet obstruction (BOO)	↓ uroflow + ↑ detrusor pressure ^[12] — defined urodynamically, not clinically
Detrusor underactivity (DUA)	↓ uroflow + ↓ detrusor pressure ^[12]

BOO is a urodynamic diagnosis! ^[12]

This is conceptually important and frequently tested ^[7]:

Bladder outlet obstruction (BOO): defined urodynamically (high Pdet + low flow rate) ^[7]
Lower urinary tract symptoms (LUTS): defined clinically ^[7]
Benign prostatic enlargement (BPE): LUTS + clinically enlarged prostate on DRE ^[7]

Different patients have different components of the three — small prostate ≠ no BOO; TURP targets BOO but may not solve all LUTS. Treatment should be individualised. ^[7]

The overall approach follows a logical sequence: screen for reversible causes → characterise the type clinically → perform basic investigations → consider advanced investigations if needed (especially before surgery).

3. Investigation Modalities — Detailed Breakdown

3.1 Bedside / First-Line Investigations

Bladder diary: urine output, voiding pattern, fluid intake pattern ^[6]

What it is: The patient records every void (time, volume), every fluid intake (time, volume, type), every episode of leakage, and any associated triggers/urgency, for ≥ 3 days ^[7]^[2]
Why it matters: This is arguably the single most informative non-invasive investigation. It tells you:

Finding on Bladder Diary	Interpretation	Why
High total 24h urine volume ( > 2.5–3L)	Polyuria	Excess fluid intake, DM, DI, diuretics → the incontinence may simply be from volume overload
Nocturnal polyuria ( > 33% of 24h output at night)	Nocturnal polyuria	CHF, peripheral oedema redistribution, sleep apnoea, habit → explains nocturia
Frequent voiding of small volumes ^[6]	OAB / detrusor overactivity	Bladder capacity functionally reduced by involuntary contractions → patient voids frequently to avoid leakage
Normal volume per void but too frequent	Polyuria or excess intake	Calculate total output; if high → polyuria workup
Large voided volumes with infrequent voids	Possible overflow pattern	Bladder over-distended before voiding occurs

Perform voiding diary / frequency-volume chart: at least 3 days, especially if frequency / nocturia ^[6]

Urine C/ST ^[6] — Urinalysis and C/ST: to rule out UTI ^[7]

Purpose: Rule out UTI (a treatable, transient cause of urge incontinence), haematuria (may indicate bladder pathology — stones, tumour), glycosuria (undiagnosed DM)
Key findings:

Finding	Significance
Leukocytes + nitrites	UTI → treat first, then reassess incontinence
Haematuria	Consider bladder tumour, stones, glomerular disease → further investigation needed (cystoscopy, imaging)
Glycosuria	Undiagnosed/poorly controlled DM → polyuria, also neuropathy risk
Proteinuria	Renal disease, possible cause of polyuria

Method: Bladder scan (ultrasound) immediately after voiding, or catheterisation
What it tells you: How much urine is left in the bladder after the patient's best effort to empty

PVR Finding	Interpretation	Why
< 50 mL ^[12]	Normal	Bladder empties well
50–200 mL	Borderline (interpret with age: 0 mL ideal in young, accept up to 100–200 mL in elderly) ^[12]	Some degree of impaired emptying, may be normal in elderly
> 200 mL	Significant retention	Either BOO or DUA → further investigation with uroflowmetry / urodynamics
≥ 300 mL in a patient unable to void	Urinary retention ^[13]	Requires catheterisation
≥ 1L	Chronic retention of urine ^[13]	Likely neurogenic or chronic obstruction; check RFT for obstructive nephropathy

The bladder was full and palpable in the suprapubic region ^[4] — in the theme case, this indicated retention requiring AROU → Foley insertion + documentation of first catheterisation urine volume, send urine for C/ST ^[4].

Method: Patient stands (or lies with full bladder) and coughs vigorously while the examiner observes the urethral meatus
Positive test: Visible leakage simultaneous with cough = supports clinical diagnosis of stress UI
Why it works: Coughing raises intra-abdominal pressure. If the urethral sphincter mechanism is weak, the pressure exceeds urethral resistance and urine leaks
Evidence of urine leakage upon straining (stress urinary incontinence) ^[4]

Testing for Occult Stress Incontinence

In a patient with significant pelvic organ prolapse, the cough test should be repeated after reducing the prolapse (e.g. with a ring pessary or Sims speculum supporting the prolapsed tissue). If the test is negative with prolapse in situ but positive after reduction, this confirms occult stress incontinence — the prolapse was kinking the urethra and masking the incontinence. This must be done before prolapse surgery to plan for a combined anti-incontinence procedure ^[1].

Method: Patient wears a pre-weighed pad for 1 hour (short test) or 24 hours (long test) during standardised activities (drinking, walking, coughing, stair climbing)
Positive test: Weight gain ≥ 1g (1-hour test) or ≥ 4g (24-hour test)
Purpose: Objective quantification of urine loss; useful when the patient reports leakage but it cannot be demonstrated on examination

RFT (obstructive uropathy) and glucose (DM is a risk factor) ^[7]

Blood Test	Why	Key Findings
RFT (creatinine, eGFR, urea) ^[7]	Screen for obstructive uropathy (bilateral obstruction → post-renal AKI), CKD	Elevated creatinine suggests upper tract compromise — urgent if overflow pattern
Fasting glucose / HbA1c ^[7]^[2]	DM causes polyuria (osmotic diuresis) and autonomic neuropathy (detrusor underactivity)	Elevated glucose → manage DM; neuropathy workup if suspected
Calcium	Hypercalcaemia causes polyuria (nephrogenic DI)	Elevated → malignancy workup, PTH
TFT	Hyperthyroidism → polyuria; hypothyroidism → constipation (exacerbates incontinence)	Usually second-line
PSA (in males) ^[7]	Controversial, probably not indicated but often taken. EAU 2017: measured if dx of CA prostate will change Mx ^[7]	Elevated → further prostate workup. Do NOT take PSA in AROU → false elevation (to be done 4–6 weeks later) ^[13]

International Prostate Symptom Score (IPSS) [7]

Use: quantify severity of LUTS, predict treatment response, guide Tx decision and monitor response to Tx (NOT a diagnostic tool) ^[7]
Involves: ^[7]
- Voiding symptoms: incomplete emptying, intermittency, weak stream, straining
- Storage symptoms: frequency, urgency, nocturia
- Quality of life measure
Interpretation: mild (1–7), moderate (8–19), severe (20–35) ^[7]
Despite its name, it can be used in both sexes for quantifying LUTS severity

Other validated questionnaires (for women specifically):

ICIQ-SF (International Consultation on Incontinence Questionnaire — Short Form): widely used, covers frequency, volume, impact on QoL, and type of incontinence
King's Health Questionnaire: assesses QoL impact across multiple domains
UDI-6 (Urogenital Distress Inventory): brief screening tool

Uroflowmetry: screening for BOO (does not rule out DUA!) ^[7]

What it is: A non-invasive test where the patient urinates into a funnel device that measures the volume of urine accumulated over time, generating a flow-time curve ^[12].

Procedure: Patient voids with a comfortably full bladder into the uroflowmeter. Uroflow requires voided volume > 150 mL to be valid ^[12]^[6]. Post-void residual (PVR) is measured immediately after by bladder scan.

Key findings and interpretation:

Parameter	Normal	Abnormal	What It Means
Flow curve pattern	Bell-shaped ^[12]	↓ peak (BPH): flattened curve; Plateaued (urethral stricture): constant low flow ^[12]	Shape gives a clue to the nature of obstruction
Peak flow rate (Qmax)	> 15 mL/s (M); > 30 mL/s (F) ^[12]	< 15 mL/s (M) suggests possible BOO	Significance: 90% no BOO if Qmax > 15 mL/s; 60% if 10–15; 33% if < 10 ^[12]
Qmax < 10 mL/s ^[6]	—	Strongly suggestive of BOO	Better outcome after TURP if Qmax < 10 ^[6] — prognostic value
Strain pattern	Single smooth peak	Multiple peaks (abnormal strain pattern) ^[6]	Patient using abdominal muscles to push urine out → either obstruction or detrusor weakness
Post-void residual	< 50 mL ^[12]	< 150 mL generally acceptable; > 200 mL significant ^[6]	Elevated PVR → either BOO or DUA

Critical Caveat

Uroflowmetry alone is NOT sufficient to diagnose outlet obstruction! ^[12] A low Qmax can be caused by either BOO or DUA — both produce a ↓ flow rate. You cannot distinguish between the two without measuring detrusor pressure simultaneously, which requires urodynamics. Additionally, 18% of patients have obstruction despite Qmax > 15 mL/s ^[12]. Uroflowmetry is a screening tool, not a definitive diagnostic test.

Urodynamic study to differentiate type if history not diagnostic ^[6]

Urodynamics: gold-standard for dx of BOO ^[7]

Cystometry is basically a portion of urodynamic studies ^[4]

What it is: A comprehensive assessment of bladder and urethral function during filling and voiding phases. It measures pressures, flow rates, volumes, and sphincter activity simultaneously.

Indications: ^[12]

Clinical type uncertain (especially mixed incontinence)
Suspicious for non-BPH cause: history of neurological disease, young age < 50 years ^[12]
Failed initial treatment ^[12]
Before surgical intervention (essential to confirm the diagnosis you are operating on) ^[4]
Suspected DSD, neurogenic bladder

Procedure: ^[12]

A dual-lumen catheter is inserted into the bladder via the urethra (one lumen fills, one measures intravesical pressure)
A rectal catheter is placed (measures intra-abdominal pressure as a surrogate)
Detrusor pressure (Pdet) = Intravesical pressure (Pves) − Intra-abdominal pressure (Pabd) ^[12]
The bladder is slowly filled with saline (or contrast, if videourodynamics)
During filling phase (cystometry): record first sensation of filling, first desire to void, strong desire to void, maximum cystometric capacity; look for involuntary detrusor contractions
During voiding phase (pressure-flow study): patient voids → measure Pdet and flow rate simultaneously
Additional: uroflowmetry integrated; sphincter EMG (usually not done in routine practice) ^[12]; contrast cystogram to assess reflux and voiding function ^[12]

Key findings and interpretation:

Phase	Finding	Diagnosis	Why
Filling	Leakage with ↑ Pabd, NO detrusor contraction	Urodynamic stress incontinence (USI) ^[1]^[4]	Proves that leakage is from raised abdominal pressure overcoming a weak sphincter, NOT from an involuntary bladder contraction
Filling	Involuntary detrusor contractions (rise in Pdet during filling that the patient cannot suppress)	Detrusor overactivity (DO) ^[1]	Proves the bladder is contracting when it shouldn't be
Voiding	↓ Qmax + ↑ Pdet	BOO ^[12]	The bladder is squeezing hard (high pressure) but urine isn't flowing well (low flow) → obstruction
Voiding	↓ Qmax + ↓ Pdet	Detrusor underactivity (DUA) ^[12]	The bladder isn't squeezing adequately → low pressure AND low flow
Filling	Simultaneous detrusor contraction + sphincter contraction	Detrusor-sphincter dyssynergia (DSD)	Both contract at once → very high pressures → danger to upper tract
Filling	Reduced cystometric capacity, early first desire to void	Reduced compliance or overactivity	May indicate fibrosis (post-radiation) or neurogenic cause

Specific urodynamic measurements for incontinence:

Leak point pressure (LPP): the abdominal (Pabd) or detrusor (Pdet) pressure at which leakage occurs ^[2]
- Abdominal LPP (Valsalva LPP): < 60 cmH₂O suggests intrinsic sphincter deficiency; > 90 cmH₂O suggests urethral hypermobility
- Clinical significance: helps determine which surgical approach is best
Urethral pressure profilometry (UPP): measures urethral pressure along its length → generates a urethral pressure profile ^[2]
- Maximum urethral closure pressure (MUCP) = maximum urethral pressure − bladder pressure
- Low MUCP ( < 20 cmH₂O) suggests intrinsic sphincter deficiency

From the theme case: the diagnosis from the filling phase cystometrogram was stress urinary incontinence ^[4] — meaning they saw leakage with increased abdominal pressure and no involuntary detrusor contraction.

When Do You NEED Urodynamics?

Not every patient needs urodynamics. For a straightforward case (e.g. young multiparous woman with pure stress symptoms, positive cough test, no voiding symptoms), conservative management can be started empirically. Urodynamics is reserved for: (1) diagnostic uncertainty, (2) failed conservative treatment, (3) before surgery, (4) neurological component suspected, (5) recurrent incontinence after previous surgery ^[12]^[6].

Cystoscopy ^[6]

What it is: Direct visualisation of the bladder interior using a camera
Types: Flexible (under LA, outpatient) vs rigid (under GA, allows biopsy/therapeutic intervention) ^[6]
Indications in UI workup:
- Haematuria (to rule out bladder tumour)
- Suspected bladder pathology (stones, tumour, foreign body, diverticulum)
- Recurrent UTI (looking for structural cause)
- Suspected fistula (VVF — may see the fistula opening in the bladder wall)
- NOT routinely indicated in straightforward stress or urge UI

Finding	Significance
Bladder tumour	Cause of haematuria and irritative LUTS / urgency
Bladder stone	Cause of irritative symptoms and urgency
Trabeculation of bladder wall	Chronic BOO → detrusor hypertrophy (the muscle works harder against the obstruction and becomes thickened, like a bodybuilder)
Diverticulum	Outpouching from chronic high pressures; site of stagnant urine → recurrent UTI
Fistula opening	Confirms VVF or uretero-vesical fistula
Urethral stricture	Identified during passage of scope

Imaging is not routinely first-line for UI but is indicated in specific situations:

Modality	When to Use	Key Findings
KUB (plain X-ray) ^[4]	AROU (to check for stones, faecal loading); immediate action for AROU: Foley insertion + KUB ^[4]	Radio-opaque stones, faecal loading in rectum/colon
Renal/bladder USG	Elevated PVR, elevated RFT (check for hydronephrosis), palpable mass	Hydronephrosis (obstruction), bladder wall thickening, large PVR, renal masses, adnexal masses
Transvaginal USG ^[14]	PV detect adnexal mass + urinary incontinence → transvaginal US is the most appropriate imaging ^[14]	Pelvic masses (fibroid, ovarian tumour) that may compress bladder; also assesses bladder neck position
CT urogram	Haematuria workup (to rule out upper tract tumour, stones) ^[6]	Non-contrast: stones; parenchymal phase: tumours; excretory phase: urothelial lesions
MRI pelvis	Suspected fistula (best modality for delineating fistula tract), neurological causes (MRI spine for cauda equina / cord lesion)	Fistula tract, disc herniation, cord compression, tethered cord
Micturating cystourethrogram (MCU) ^[15]	Most commonly paediatric patients; vesicoureteric reflux; study of urethral anatomy during micturition ^[15]	VUR (contrast refluxing up ureters during voiding), posterior urethral valves in boys, urethral diverticulum

4. Special Investigation Scenarios

This is the exact approach demonstrated in the O&G theme case and is highly testable:

Immediate action for AROU: Foley insertion + documentation of first catheterisation urine volume + send urine for C/ST ^[4]
KUB ^[4]
Discharge plan: Ring pessary + teach pelvic floor exercises + bladder training ^[4]
Follow-up with frequency-volume chart ^[4]
When conservative management failed (pessary fell out) → cystometry arranged ^[4]
Filling phase cystometrogram → diagnosis of stress urinary incontinence ^[4]
Then proceed to surgical planning (if patient opts for surgery)

Assess degree of prolapse in relation to introitus + ask patient to cough / bear down ^[4]

Can use the speculum to determine the compartment of prolapse ^[4]

POP-Q score (Pelvic Organ Prolapse Quantification) ^[4] — the standardised scoring system that uses 6 defined points on the vaginal wall, measured in centimetres relative to the hymen:

Negative values = above the hymen
Zero = at the hymen
Positive values = below the hymen (prolapsing beyond introitus)

Focused lower limb neurological examination (power, reflexes, sensation)
Perianal sensation, anal tone, bulbocavernosus reflex (BCR, S2-4) ^[2]
- BCR: anal sphincter contraction upon squeezing of glans penis/clitoris/tugging on Foley ^[10] — tests the S2-4 sacral reflex arc
- Absent BCR → suggests LMN lesion (sacral cord/cauda equina)
MRI whole spine if cauda equina syndrome suspected ^[10]
Video-urodynamics with EMG: for DSD characterisation

Clinical Question	Investigation	Expected Finding
Is there a UTI?	Urinalysis + C/ST	Leukocytes, nitrites, positive culture
How much is the patient voiding and when?	Bladder diary (≥ 3 days)	Frequency, volume patterns, triggers
Is there urinary retention?	Bladder scan / PVR	Elevated PVR > 200 mL
Is there obstruction? (screening)	Uroflowmetry	↓ Qmax, abnormal flow pattern
Is it BOO or DUA?	Urodynamic studies	BOO: ↓ flow + ↑ Pdet; DUA: ↓ flow + ↓ Pdet
Is it true stress incontinence?	Cough stress test (bedside) → Urodynamics (definitive)	Leakage with ↑ Pabd, no detrusor contraction
Is it detrusor overactivity?	Urodynamics (filling cystometry)	Involuntary detrusor contractions during filling
Is there a bladder tumour/stone/fistula?	Cystoscopy	Direct visualisation of pathology
Is there upper tract damage?	RFT + renal USG	Elevated creatinine, hydronephrosis
Is there a pelvic mass causing compression?	Transvaginal USG	Fibroid, ovarian mass
Is there a neurological cause?	Neuro exam + MRI spine	Absent BCR, cauda equina findings on MRI
Is there a fistula?	MRI pelvis ± cystoscopy ± dye test	Fistula tract visualised
What is the severity of LUTS?	IPSS	Mild (1-7), moderate (8-19), severe (20-35)

High Yield Summary

Diagnosis of UI is clinical first, urodynamic second. History + bladder diary + cough test can diagnose most cases.

Clinical vs Urodynamic terminology (must know): SUI ↔ USI; OAB/UUI ↔ Detrusor overactivity. Haylen 2010 IUGA/ICS definitions.

Basic Ix for all patients: Urinalysis + C/ST, bladder diary (≥ 3 days), PVR (bladder scan), bloods (RFT, glucose).

Uroflowmetry: Screening for BOO. Needs voided volume > 150 mL. Qmax > 15 = 90% no BOO. Cannot distinguish BOO from DUA alone. Not sufficient to diagnose obstruction by itself.

Urodynamics: Gold standard. Pdet = Pves − Pabd. Filling phase diagnoses USI and DO. Voiding phase diagnoses BOO vs DUA. Essential before surgery.

BOO is a urodynamic diagnosis — not clinical, not by uroflowmetry alone.

IPSS: Quantifies LUTS severity (mild/moderate/severe). NOT a diagnostic tool.

Theme case approach: AROU → Foley + document volume + C/ST + KUB → conservative Mx → if fails → cystometry → plan surgery.

Occult stress incontinence: Test by reducing prolapse then performing cough test.

PSA pitfall: Do NOT check PSA during AROU — false elevation. Wait 4-6 weeks.

Active Recall - Diagnosis and Investigation of Urinary Incontinence

References

^[1] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p53) ^[2] Senior notes: Ryan Ho Urogenital.pdf (p159, p161) ^[4] Lecture slides: Block C - O&G Theme Case 4.pdf (p3, p4, p5, p6) ^[6] Senior notes: Maksim Surgery Notes.pdf (p309, p316) ^[7] Senior notes: Ryan Ho Fundamentals.pdf (p354, p355); Ryan Ho Urogenital.pdf (p170) ^[8] Senior notes: Ryan Ho Neurology.pdf (p53) ^[10] Senior notes: Maksim Medicine Notes.pdf (p47) ^[12] Senior notes: Ryan Ho Fundamentals.pdf (p356, p357); Ryan Ho Urogenital.pdf (p171) ^[13] Senior notes: Ryan Ho Fundamentals.pdf (p352) ^[14] Senior notes: Ryan Ho Radiology.pdf (p40) ^[15] Senior notes: Ryan Ho Diagnostic Radiology.pdf (p23)

Management of Urinary Incontinence

The overarching principle of management is simple: treat the underlying cause, treat reversible factors first, start conservative, and escalate only when needed. The management pathway is different for each type of incontinence, but they all share this philosophy.

Management: treat underlying cause! ^[2]

1. General Principles

Before diving into type-specific treatments, there are universal management steps for ALL patients with UI:

Always screen for and treat DIAPPERS causes before committing to long-term management:

Treat UTI (antibiotics → reassess)
Review and modify offending medications
Treat constipation (faecal impaction → disimpaction, then laxative regimen)
Address delirium (treat precipitant)
Manage polyuria (optimise DM control, reduce excessive fluid/caffeine)
Treat atrophic vaginitis (topical oestrogen)
Improve mobility / provide accessible toileting

Initial management: Behavioural therapy — smoking cessation, weight reduction, reduce caffeine intake, fluid intake advice (8 glasses of water is a myth!) ^[16]^[17]

Lifestyle: weight loss, reduce caffeine intake, smoking cessation ^[6]

Modification	Mechanism / Why It Helps
Weight reduction ^[6]^[16]	Reduces chronic intra-abdominal pressure on the pelvic floor → less stress on weakened support structures; even 5-10% weight loss significantly improves SUI
Reduce caffeine intake ^[6]^[16]	Caffeine is both a bladder irritant (stimulates detrusor) and a mild diuretic → increases frequency and urgency
Smoking cessation ^[6]^[16]	(1) Chronic cough from smoking → repetitive pelvic floor stress → worsens SUI; (2) Nicotine may stimulate detrusor overactivity
Fluid intake advice ^[16]	Not too much (overwhelms bladder capacity) and not too little (concentrated urine irritates bladder mucosa). 8 glasses of water is a myth ^[16] — advise ~1.5L/day, adjusted to activity and climate
Reduce alcohol ^[2]	Alcohol is a diuretic + sedative → polyuria + impaired awareness of bladder fullness
Manage constipation ^[2]	Chronic straining weakens pelvic floor; faecal loading compresses bladder/urethra

Protective pads/garments: risk of contact dermatitis or infections ^[2] — these are containment measures, not treatment. Use them as a bridge while definitive management takes effect.

External (condom) catheters: preferred to indwelling ones ^[2] — less risk of CAUTI and urethral trauma.

Patients usually do not volunteer incontinence symptoms due to: embarrassment, accepting it as part of normal ageing and childbirth, not aware that treatment is available, symptom not troublesome enough. Always take note of the symptom and refer if indicated ^[18].

3. Type-Specific Management

3.1 Stress Urinary Incontinence (SUI)

The management ladder: conservative → pharmacological → surgical. Always start conservative.

Stress UI: pelvic floor muscle training ± biofeedback (repeated sets, repetition of contraction and relaxation) ^[6]

Intervention	Details	Mechanism / Why It Works
Pelvic floor muscle training (PFMT / Kegel exercises) ^[2]^[6]	3 sets of 8-12 contractions for 8-10 seconds each, performed TDS, for ≥ 15-20 weeks ^[2]	Strengthens the levator ani and periurethral muscles → improves the "hammock" support under the urethra → when abdominal pressure rises, the urethra is better compressed against a stronger support → less leakage. This also improves the guarding reflex (reflexive sphincter contraction during cough).
Biofeedback ^[2]^[6]	Placement of vaginal pressure sensor → live feedback of strength of pelvic floor contractions → associated with better outcome than PFMT alone ^[2]	Many women (up to 50%) perform Kegel exercises incorrectly — they bear down instead of squeezing. Biofeedback lets the patient and therapist see whether the correct muscles are contracting and how strong the contraction is.
Vaginal pessary	Ring pessary or incontinence pessary placed in vagina	Mechanically supports the urethra and bladder neck, restoring anatomical position → re-establishes the hammock effect. Useful when prolapse coexists.
Vaginal cones / weights	Weighted cones inserted into vagina; patient maintains in place by contracting pelvic floor	Progressive resistance training for pelvic floor muscles

Drug	Mechanism	Details
Duloxetine ^[2]	SNRI → ↑ 5-HT/NA activity in Onuf's nucleus → ↑ urethral sphincter activity ^[2]	Onuf's nucleus (S2-S4) contains the motor neurons that innervate the external urethral sphincter. By increasing serotonin and noradrenaline at these synapses, duloxetine enhances the tonic activity of the sphincter → increased urethral closure pressure. Not licensed in HK ^[2]. Used in some countries as an adjunct when surgery is not desired. Side effects: nausea (most common), dizziness, dry mouth.
Vaginal oestrogen (topical) ^[2]	Restores urethral mucosal coaptation, improves submucosal vascular cushion, improves periurethral connective tissue	Suitable for postmenopausal women with vaginal atrophy ^[2]. Does NOT improve stress incontinence definitively on its own but improves tissue quality and is useful as an adjunct. Available as cream, pessary, or ring. Important: systemic HRT does NOT improve and may worsen UI — only topical vaginal preparations are recommended.

Discuss the usual indication for surgical and non-surgical management for pelvic organ prolapse and stress urinary incontinence ^[3]

Procedure	Technique	Indication	Mechanism	Complications
Mid-urethral sling (MUS): Tension-free vaginal tape (TVT) ^[6] / Trans-obturator tape (TOT) ^[2]	A synthetic polypropylene mesh tape is placed under the mid-urethra via a minimally invasive vaginal approach. TVT passes retropubically; TOT passes through the obturator foramen.	First-line surgical option for female SUI	The tape acts as a new "hammock" — during cough/strain, the urethra is compressed against the tape → restores continence. It is "tension-free" because it is not pulled tight but rather acts as a passive support.	Bladder perforation (TVT > TOT), voiding difficulty (tape too tight), mesh erosion into vagina or urethra, groin pain (TOT), de novo urgency, infection. 2024 note: Mesh complications have led to significant regulatory scrutiny; in some countries, full mesh slings are restricted — always discuss risks.
Burch colposuspension ^[2]	Suture lateral vaginal walls to iliopectineal (Cooper's) ligaments → bladder neck lifted ^[2]	Alternative to MUS; good for women who also need abdominal surgery (e.g. concomitant hysterectomy)	Elevates and stabilises the bladder neck → restores its intra-abdominal position so that rises in abdominal pressure are transmitted equally to both bladder and urethra	Voiding difficulty, de novo urgency (10-20%), enterocele formation, longer recovery than MUS
Transurethral bulking agent injection ^[2]	Bulking agents (e.g. silicone, collagen, polyacrylamide hydrogel) injected via cystoscope to mid-urethra ^[2]	Intrinsic sphincter deficiency (ISD); elderly/unfit for major surgery; failed MUS	Injected material increases the bulk of the submucosal tissue → improves mucosal coaptation → ↑ urethral closure pressure	Less invasive but less durable than MUS (may need repeated injections); migration of material; UTI; urinary retention
Artificial urinary sphincter (AUS) ^[2]	An inflatable cuff around the urethra, a pressure-regulating balloon, and a control pump (in labia or scrotum). Patient deflates cuff before voiding.	Most effective treatment for male SUI ^[2] (post-prostatectomy); severe female ISD refractory to other surgery	Cuff maintains constant circumferential pressure around urethra → complete occlusion; deflated voluntarily for voiding	Mechanical failure, erosion, infection (may require explantation), urethral atrophy
Fascia lata sling ^[6]	Autologous fascial strip harvested from thigh → placed under urethra as a sling	Alternative to synthetic mesh in patients who want to avoid mesh	Same hammock principle as MUS but uses patient's own tissue → no mesh erosion risk	Donor site morbidity (thigh pain, seroma), longer operative time

TVT vs TOT — How to Choose?

TVT (retropubic): Slightly higher cure rate for ISD; higher risk of bladder perforation (intraoperative cystoscopy mandatory). TOT (transobturator): Easier, faster, lower risk of bladder/bowel injury; slightly higher risk of groin pain; may be less effective for severe ISD. For most women with urethral hypermobility-type SUI, either is acceptable. For ISD, TVT or bulking agents are preferred.

3.2 Urge Urinary Incontinence (UUI) / Overactive Bladder (OAB)

The management ladder: conservative → pharmacological → advanced therapies.

Urge UI: bladder training ^[6]

Intervention	Details	Mechanism
Bladder training ^[2]^[6]	Timed voiding with controlling of urgency by distraction or mental relaxation techniques ^[2]. Patient starts with short voiding intervals (e.g. every 1 hour) then gradually extends by 15-30 minutes per week until reaching 3-4 hour intervals.	Re-trains the cortical inhibition of the micturition reflex. By learning to suppress urgency signals (distraction, deep breathing), the brain gradually regains its ability to inhibit the pontine micturition centre → ↓ involuntary detrusor contractions.
Pelvic floor exercises (PFMT) ^[2]	Same as for SUI (3 sets of 8-12 contractions, TDS, ≥ 15-20w)	Voluntary pelvic floor contraction sends an inhibitory signal to the detrusor via the "guarding reflex" (pudendal nerve activation reflexively inhibits parasympathetic outflow) → helps suppress urgency
Biofeedback ^[2]	As for SUI	Enhances correct PFMT technique → better urgency suppression

Urge UI: anti-ACh (e.g. oxybutynin, solifenacin), β3-agonist (mirabegron), Botox injection ^[6]

Medical therapy: check for C/I to anticholinergics, usually require ~4 weeks to see full benefit ^[2]

A. Anticholinergics (Antimuscarinics)

These are the traditional mainstay of OAB pharmacotherapy. They work by blocking muscarinic receptors (primarily M3) on the detrusor muscle → reduce involuntary contractions during filling.

Drug	Selectivity	Key Points
Oxybutynin ^[6]^[2]	Non-selective (M1, M2, M3)	Oldest and cheapest. High rate of side effects due to non-selectivity (especially M1 in CNS → cognitive impairment). Extended-release (ER) and transdermal patch formulations reduce side effects.
Tolterodine ^[2]	Relatively non-selective	Better tolerated than oxybutynin IR; available as ER formulation
Solifenacin ^[6]^[2]	M3-selective	Better side effect profile than oxybutynin; once-daily dosing
Darifenacin	M3-selective	Minimal CNS penetration → least cognitive side effects (good for elderly)
Fesoterodine	Non-selective (active metabolite of tolterodine)	Dose flexibility
Trospium	Non-selective, quaternary amine	Does NOT cross blood-brain barrier → no CNS side effects; excellent for elderly

Side effects of anticholinergics: dry mouth, dry eye, constipation, cognitive impairment ^[6]

Side Effect	Mechanism	Clinical Significance
Dry mouth	Blockade of M3 receptors on salivary glands → ↓ saliva	Most common reason for discontinuation
Dry eyes	Blockade of M3 on lacrimal glands → ↓ tear production	Problematic in contact lens wearers
Constipation	Blockade of M3 on GI smooth muscle → ↓ peristalsis	Ironic: constipation worsens pelvic floor problems!
Cognitive impairment	Blockade of M1 receptors in CNS → ↓ cholinergic transmission	Major concern in elderly — can worsen or mimic dementia. Avoid oxybutynin in elderly. Prefer M3-selective or trospium.
Urinary retention	Over-suppression of detrusor contractility	C/I if PVR > 150 mL due to risk of AROU ^[6]
Tachycardia	Blockade of M2 on heart	Usually mild
Blurred vision	Blockade of M3 on ciliary muscle → ↓ accommodation
Acute angle-closure glaucoma	↑ intraocular pressure if predisposed	Absolute C/I: uncontrolled narrow-angle glaucoma

Anticholinergics in the Elderly

The Beers Criteria and STOPP criteria both flag anticholinergics as potentially inappropriate in older adults due to cognitive side effects. In an elderly patient with OAB, prefer: (1) non-pharmacological therapy first, (2) if drugs needed, use M3-selective agents (solifenacin, darifenacin) or trospium (doesn't cross BBB), (3) AVOID oxybutynin IR. Also avoid in patients already on cholinesterase inhibitors for dementia — the two drugs work against each other.

B. Beta-3 Adrenergic Agonist

Beta-3 agonist: mirabegron ^[6]

Drug	Mechanism	Key Points
Mirabegron	Agonist at β3-adrenergic receptors on detrusor muscle → promotes detrusor relaxation during filling phase	Alternative to anticholinergics — no anticholinergic side effects (no dry mouth, no cognitive impairment). Can be combined with low-dose anticholinergics for synergistic effect.
Vibegron (newer)	Same mechanism as mirabegron	Less CYP2D6 interaction than mirabegron

Side effect of mirabegron: elevated BP ( > 10%) ^[6]

Side Effect	Mechanism	Clinical Action
Hypertension	β3 agonism also present on vascular smooth muscle → ↑ BP	Monitor BP. C/I: severe uncontrolled hypertension (BP ≥ 180/110). Use with caution if existing HTN.
UTI, headache, nasopharyngitis	Unrelated to mechanism	Common but mild
Tachycardia (rare)	β-adrenergic stimulation	Monitor in patients with cardiac history

C. Topical Oestrogen

Vaginal oestrogen: suitable for postmenopausal women with vaginal atrophy ^[2]

Mechanism: Restores urethral and bladder trigone epithelium (both embryologically derived from the same urogenital sinus) → reduces mucosal irritation → ↓ afferent signals → ↓ urgency/frequency.

D. Desmopressin

Desmopressin: suitable for persistent nocturia ^[2]

Mechanism: Synthetic analogue of ADH → promotes water reabsorption in collecting ducts → ↓ urine production at night. Must monitor serum sodium (risk of hyponatraemia, especially in elderly). C/I: heart failure, hyponatraemia, renal impairment.

Surgical therapy: percutaneous sacral nerve stimulation, Botox injection, augmentation cystoplasty, diversion ^[2]

Therapy	Mechanism	Indication	Key Points
Botulinum toxin A (Botox) injection ^[6]^[2]	Injected into detrusor wall via cystoscope → blocks ACh release at neuromuscular junction → ↓ detrusor contractility	Refractory OAB failing conservative + pharmacotherapy	Effective for 6-9 months → requires repeat injections. Risk of urinary retention (need to teach patient CISC before injection). Dose: 100-200 units for idiopathic OAB; 200-300 units for neurogenic DO.
Percutaneous sacral nerve stimulation (SNS / InterStim) ^[2]	Electrode placed at S3 foramen → modulates sacral nerve activity → restores balance between excitatory and inhibitory signals to detrusor	Refractory OAB; also useful for urinary retention from DUA	Two-stage procedure: test stimulation → if > 50% improvement, permanent implant. MRI compatibility is now available with newer devices.
Percutaneous tibial nerve stimulation (PTNS)	Needle electrode near posterior tibial nerve (at ankle) → retrograde stimulation of S2-S4 via the tibial nerve → neuromodulation of bladder	Alternative to SNS; less invasive	Weekly 30-minute sessions for 12 weeks, then monthly maintenance. Less effective than SNS but avoids surgery.
Augmentation cystoplasty ^[2]	Detubularised segment of ileum is sewn onto the opened bladder → increases bladder capacity and reduces detrusor pressure	Last resort for intractable OAB / neurogenic DO (e.g. SCI with dangerous high-pressure bladder)	Major surgery. Patient must perform lifelong CISC (the augmented bladder cannot contract effectively). Risks: metabolic acidosis (NAGMA — ileum reabsorbs NH₄Cl), mucus production, bladder stones, rare malignancy risk in the ileal segment.
Urinary diversion ^[2]	Ileal conduit or continent diversion (e.g. Mitrofanoff)	Absolute last resort	Permanent stoma (ileal conduit) or self-catheterisable channel (Mitrofanoff via appendix to umbilicus). Reserved for patients where all else has failed or bladder must be removed.

3.3 Overflow Incontinence

The key principle: relieve the obstruction (if BOO) or ensure regular bladder emptying (if DUA). The management is fundamentally different depending on which mechanism is at play.

AROU → Foley insertion + documentation of first catheterisation urine volume, send urine for C/ST ^[4]

Immediate bladder decompression by urethral catheterisation (first-line) by 14-18 Fr Foley catheter ^[13]

Step	Details	Why
1. Catheterise	14 Fr Foley catheter, aseptic technique, xylocaine jelly ^[13]	Immediate relief of retention; document volume drained
2. Send urine C/ST	From catheterised specimen	Rule out UTI as precipitant
3. Bloods	CBC, RFT, glucose	Leukocytosis (infection), elevated creatinine (obstructive nephropathy), hyperglycaemia (DM)
4. KUB	Plain X-ray ^[4]	Check for stones, faecal loading
5. Do NOT check PSA	^[13]	AROU causes false elevation; check 4-6 weeks later

If catheter cannot be passed: ^[6]^[13]

Enlarged prostate → use thicker catheter (20-22 Fr) — stiffer, easier to navigate past enlarged gland
Urethral stricture → use thinner catheter (10-12 Fr)
If still fails → Tiemann catheter (curved tip) → cystoscopic-guided insertion → urethral dilators
If all fail → suprapubic catheterisation (SPC) ^[13]

SPC indications: failed urethral catheterisation, Hx of urethral trauma, long-term drainage expected ( > 3 weeks) ^[13]

SPC C/I: non-distended bladder, uncorrected bleeding tendency, known/suspected urothelial CA ^[13]

For BPH (most common cause of overflow in males):

Prescribe alpha-blocker (Xatral) + trial wean-off catheter (TWOC) later ^[6]

Treatment	Details	Mechanism
Alpha-1 adrenergic blockers (first-line medical) ^[6]	Non-selective: prazosin, terazosin, doxazosin, alfuzosin ^[6]; Selective α1A: tamsulosin, silodosin ^[6]	Relax smooth muscles in prostate and bladder neck (NOT body) ^[6] → reduces dynamic component of obstruction. Onset: days to weeks.
5-alpha reductase inhibitors (5ARI) ^[6]	Finasteride, dutasteride ^[6]	Reduce DHT → decrease size of prostate + decrease vascularity + progression prevention ^[6]. Slow onset (3-6 months for max effect). Preferred for larger glands ≥ 30-40 mL (TRUS) / IPSS ≥ 12 ^[6]. 50% decrease in PSA — multiply PSA by 2 when screening for CA prostate. ^[6]
Combination therapy	α-blocker + 5ARI	For large prostates with bothersome symptoms; better long-term outcomes than monotherapy (MTOPS trial)
PDE5 inhibitor (tadalafil) ^[6]	Daily low-dose tadalafil	Relaxes prostatic smooth muscle via NO/cGMP pathway. Avoid if using nitrate ^[6]. Bonus: also treats ED.
Anticholinergics for OAB component ^[6]	For men with BPH + predominant irritative LUTS	C/I if PVR > 150 mL due to risk of AROU ^[6]
Beta-3 agonist (mirabegron) ^[6]	For OAB component	Safer than anticholinergics in terms of retention risk

Surgical management of BPH:

Indications for surgery: failed medical therapy, recurrent complications ^[6]

Absolute indication: complications of BPH (refractory AROU, bladder stones, recurrent UTI, obstructive uropathy) ^[16]

Relative indication: bothersome symptoms despite medical treatment ^[16]

Procedure	Technique	Key Points
TURP (gold standard) ^[6]^[16]	Transurethral insertion of resectoscope → scrap pieces of prostate off using monopolar or bipolar diathermy until prostatic fibrous capsule ^[16]	Monopolar uses 1.5% glycine irrigation (risk of TUR syndrome); bipolar uses NS (safer but slower). 3-way Foley post-op to irrigate bladder with NS to avoid clot retention. ^[6]
Holmium laser enucleation (HoLEP) ^[6]	Laser enucleation of adenoma → morcellated for removal	Useful for large prostates; saline irrigation → no TUR syndrome; lower bleeding risk
PVP (Greenlight laser) ^[6]	Photoselective vaporisation	Less bleeding, good for patients on anticoagulation; no histological specimen obtained
TUIP ^[16]	Longitudinal incision in prostate → widens bladder neck	Only for small prostates ≤ 30g; lower morbidity than TURP
Minimally invasive: UroLift, Rezūm, PAE, TUMT ^[6]	Various mechanisms to reduce prostatic tissue	Newer options; generally less durable than TURP but fewer sexual side effects

TURP specific complications ^[6]:

Bleeding, infection
Perforation (can form fistula)
TUR syndrome: dilutional hypoNa + fluid overload + glycine toxicity; S/S: nausea (1st), confusion, cerebral oedema, visual disturbance; Mx: manage as hypoNa, hypertonic NS; Prevention: use bipolar (NS irrigant), limit volume < 1L and irrigation pressure < 60 mmHg ^[6]
Retrograde ejaculation (70-80%) ^[6] — due to resection of bladder neck
Urethral stricture ^[6]
Incontinence (1%): urge (early) / stress (late) ^[6]

Treatment	Details	Mechanism
Clean intermittent self-catheterisation (CISC)	Patient learns to catheterise 4-6 times daily, draining the bladder each time	Gold standard for neurogenic bladder / DUA. Prevents overdistension, reduces UTI risk vs indwelling catheter, preserves bladder compliance
Long-term catheterisation (Foley / SPC / CISC) ^[6]	For patients who cannot perform CISC (poor dexterity, cognitive impairment)	SPC preferred over long-term urethral Foley (less urethral trauma, easier care)
Bethanechol (cholinergic agonist)	Stimulates muscarinic receptors on detrusor	Rarely used — limited efficacy and significant side effects (GI cramping, bradycardia). Not recommended by current guidelines.
Sacral neuromodulation	Electrode at S3	May help some cases of non-obstructive retention

The management here is NOT urological — it's about removing barriers to toileting:

Intervention	Details
Prompted voiding	Carer asks patient regularly (every 2 hours) if they need to use the toilet → helps demented patients who cannot initiate
Timed voiding / scheduled toileting	Fixed schedule (e.g. every 2-3 hours) regardless of urge → prevents accidents
Environmental modifications	Commode by bed, raised toilet seat, adequate lighting, clothing that is easy to remove (Velcro instead of buttons)
Mobility aids	Walking frame, wheelchair access to bathroom
Carer education	Teach carers to assist with toileting; involve medical social worker
Containment	Pads, condom catheters (men), adult diapers — not treatment but improves dignity and hygiene

Cause	Treatment
Vesicovaginal fistula (VVF)	If small and diagnosed early (< 2 weeks): prolonged catheter drainage may allow spontaneous closure. If not: surgical repair (vaginal approach for small fistulae; abdominal approach for complex/high fistulae) with interposition flap (e.g. omental or Martius fat pad flap)
Ectopic ureter	Surgical re-implantation of ureter into bladder (ureteroneocystostomy) or nephroureterectomy if the associated kidney is non-functioning

3.6 Management of Coexisting Prolapse and Incontinence

This is a central theme of the O&G lecture ^[3]^[4]:

Management options: Observe / Ring pessary / Surgery ^[4]

Ring pessary ^[4]:

Foreign body, change every 4 to 6 months ^[4]
Try one size, if falls out → try bigger size, if falls out → try two, if falls out → surgery ^[4]
Also provides support to urethra → may improve coexisting SUI
Can be used to test for occult stress incontinence (if SUI appears after pessary insertion → confirms occult SUI)

Teach pelvic floor exercise + bladder training ^[4]

Medication for urge incontinence → symphony trial ^[4] (trial of anticholinergics if urgency symptoms present)

Conservative management is available but rarely curative ^[1]

If surgery is indicated, surgery for both conditions may be needed ^[1]

Procedure	Details	Considerations
Vaginal hysterectomy ^[4]	Removal of uterus vaginally → treats uterine prolapse	Remnant vault can prolapse as well ^[4] → need vault suspension
Colpocleisis ^[4]	Close the vagina ^[4]	In the future will not be able to do cervical smears or endometrial workup ^[4]. Only for elderly women certain they do not want vaginal function.
Laparoscopic sacrocolpopexy ^[4]	Not first line; have to have done vaginal hysterectomy before ^[4]; mesh attached from vaginal vault to sacral promontory	3 hours ^[4]; for younger, fitter patients with vault prolapse
Combined anti-incontinence procedure	TVT/TOT at same sitting as prolapse repair	Essential if occult SUI demonstrated on preoperative assessment

This is a special and important situation — the management depends on the type of neurological lesion:

Pattern	Examples	Bladder Type	Goal	Management
Suprapontine (detrusor overactivity, coordinated sphincter)	Stroke, PD, NPH, dementia	Reflex bladder with urgency	Reduce overactivity, prevent incontinence	Bladder training, anticholinergics/mirabegron, prompted voiding (if cognitive impairment)
Suprasacral SCI (DSD)	SCI above S2, MS	High-pressure bladder with DSD	Protect upper tract (prevent reflux nephropathy)	CISC (gold standard) + anticholinergics (to reduce detrusor overactivity) ± Botox to detrusor ± sphincterotomy if DSD refractory. Avoid indwelling catheter if possible.
Sacral / infrasacral (areflexic bladder)	Cauda equina, conus, DM neuropathy	Acontractile bladder	Ensure regular emptying, prevent overdistension	CISC (4-6 times/day), long-term catheter if CISC not possible

Genitourinary complications management in neurological patients: indwelling catheter or condom catheter (if incontinent male) → avoid bladder overdistension and genitourinary infection → intermittent catheterisation → measure post-void residual volume ^[8]

DSD — Why Is It Dangerous?

In DSD, the detrusor contracts against a closed sphincter → very high intravesical pressures → vesicoureteral reflux → hydronephrosis → renal failure. The management priority is to protect the upper tract, not just achieve social continence. CISC + anticholinergics convert the high-pressure reflex bladder into a low-pressure storage system that is emptied regularly ^[8].

Treatment	Contraindications	Why
Anticholinergics	Uncontrolled narrow-angle glaucoma, significant BOO/PVR > 150 mL, severe constipation, cognitive impairment/dementia (relative), myasthenia gravis	Glaucoma: ↑ IOP; BOO: risk of AROU; Constipation: worsens; Cognition: anti-M1 effects
Mirabegron	Severe uncontrolled HTN (BP ≥ 180/110)	β3-mediated vasorelaxation can paradoxically raise BP
Duloxetine	Uncontrolled HTN, hepatic impairment, concomitant MAOIs	Serotonergic syndrome risk; hepatotoxicity
Desmopressin	Heart failure, hyponatraemia (Na < 130), renal impairment (eGFR < 50), age > 65 (relative — need close Na monitoring)	Water retention → fluid overload, dilutional hyponatraemia
TVT/TOT (mesh sling)	Active urinary/vaginal infection, concurrent pregnancy, uncorrected coagulopathy	Infection risk; mesh complications
Botox (intravesical)	UTI at time of injection, unable/unwilling to perform CISC	Risk of retention; active infection → systemic spread
SPC	Non-distended bladder, uncorrected bleeding tendency, known/suspected urothelial CA ^[13]	Risk of bowel injury if bladder not distended; seeding of tumour along tract
Urethral catheterisation	Urethral injury (blood at meatus, high-riding prostate), recent urological surgery ^[13]	Risk of creating false passage

High Yield Summary

Universal first steps: Treat reversible causes (DIAPPERS). Lifestyle: weight loss, reduce caffeine, smoking cessation, fluid advice, manage constipation.

Stress UI ladder: (1) PFMT ± biofeedback for ≥ 15-20 weeks → (2) Duloxetine or topical oestrogen (adjunct) → (3) Surgery: mid-urethral sling (TVT/TOT) is first-line surgical; alternatives: Burch colposuspension, bulking agents, artificial sphincter (best for males).

Urge UI ladder: (1) Bladder training + PFMT → (2) Anticholinergics (oxybutynin, solifenacin) or beta-3 agonist (mirabegron) → (3) Botox injection / sacral neuromodulation / augmentation cystoplasty.

Anticholinergic side effects: Dry mouth, dry eyes, constipation, cognitive impairment, urinary retention. C/I if PVR > 150 mL, narrow-angle glaucoma, dementia. Mirabegron side effect: elevated BP.

Overflow UI: BOO → alpha-blockers ± 5ARI → TURP if failed. DUA → CISC is gold standard.

Prolapse + UI: Ring pessary + PFMT first → if fails, surgery for both conditions may be needed. Always test for occult SUI before prolapse surgery.

Neurogenic bladder: Protect upper tract in DSD (CISC + anticholinergics). Areflexic bladder → CISC.

TURP complications: TUR syndrome (hypoNa + glycine toxicity), retrograde ejaculation (70-80%), urethral stricture, incontinence (1%).

Active Recall - Management of Urinary Incontinence

References

^[1] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p73, p74) ^[2] Senior notes: Ryan Ho Urogenital.pdf (p159, p161) ^[3] Lecture slides: Block C - O&G Theme Case 4.pdf (p1) ^[4] Lecture slides: Block C - O&G Theme Case 4.pdf (p4, p5, p6) ^[6] Senior notes: Maksim Surgery Notes.pdf (p309, p317, p318) ^[7] Senior notes: Ryan Ho Fundamentals.pdf (p354, p355) ^[8] Senior notes: Ryan Ho Neurology.pdf (p53, p82) ^[13] Senior notes: Ryan Ho Fundamentals.pdf (p352); Ryan Ho Urogenital.pdf (p167) ^[16] Senior notes: Maksim Surgery Notes.pdf (p316, p317); Ryan Ho Urogenital.pdf (p176) ^[17] Lecture slides: Block C - I felt a lump below_ urinary incontinence in females; genital prolapse.pdf (p52) ^[18] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p73)

Complications of Urinary Incontinence

Urinary incontinence is not a benign nuisance — it carries significant medical, psychological, and social complications. Think of the complications in two broad categories: (1) complications of the incontinence itself (the disease) and (2) complications of its treatment (iatrogenic). Both are exam-relevant and both have logical pathophysiological explanations.

Although genital prolapse and urinary incontinence are not life-threatening conditions, they can affect the quality of life of a woman ^[3] — but this statement about quality of life should not mislead you into thinking the medical consequences are trivial. They are not.

1. Complications of Urinary Incontinence Itself

Complication	Pathophysiology	Clinical Features	Management
Incontinence-associated dermatitis (IAD)	Prolonged skin exposure to urine → alkaline pH of urine (especially if infected) damages the acid mantle of skin → disruption of epidermal barrier → irritant contact dermatitis ^[19]	Erythema, maceration, erosion in perineum, inner thighs, buttocks, inguinal folds; burning, stinging	Barrier creams (zinc oxide, dimethicone), absorbent continence products with superabsorbent polymers, frequent pad changes, gentle skin cleansing (pH-balanced), treat the incontinence itself
Secondary fungal infection (Candida intertrigo)	IAD-damaged, macerated skin in warm moist folds provides an ideal environment for Candida colonisation	Satellite lesions around erythematous base, particularly in inguinal folds and perineum	Topical antifungals (nystatin, clotrimazole) + barrier cream
Pressure ulcers	Wet skin from incontinence ↑ friction coefficient → when combined with immobility (the same elderly patients who have functional incontinence), pressure + moisture → tissue breakdown	Sacral, buttock, perineal pressure injuries	Prevention: continence management, moisture barriers, pressure-relieving surfaces, repositioning; treatment: wound care staged by severity

Protective pads/garments: risk of contact dermatitis or infections ^[2] — even the containment devices themselves can worsen skin problems if not changed frequently.

Mechanism	Type of UI Most Relevant	Details
Stagnant residual urine	Overflow incontinence	Complications of overflow incontinence: UTI, bladder stones, obstructive uropathy ^[2]. When the bladder never empties completely, the stagnant residual serves as a culture medium for bacteria. Normal voiding mechanically flushes bacteria out — without complete emptying, this defence fails.
BPH-related obstruction	Overflow (males)	BPH complications — Bladder level: AROU, recurrent UTI, bladder stone, diverticulum, chronic ROU ± overflow incontinence ^[6]
Catheter-associated UTI (CAUTI)	All types (if catheterised)	Indwelling catheters provide a direct conduit for bacterial ascent. Biofilm forms on catheter surfaces. Risk increases ~3-7% per day of catheterisation. Long-term catheterisation: risk of UTI/urosepsis, trauma, stones, urethral strictures, prostatitis and SCC of bladder ^[13]
Perineal contamination	Stress UI, functional UI	Constant wetness → perineal skin colonised with bacteria → ascending infection

Recurrent UTI risk factors include urinary incontinence, obstruction (e.g. BPH), urinary instrumentation (e.g. indwelling catheters), immunocompromised states (CKD, DM) ^[20]

Diabetic autonomic neuropathy → bladder dysfunction: ↓ ability to sense full bladder, incomplete emptying, recurrent UTI, overflow incontinence ^[21]

UTI in Overflow Incontinence — The Vicious Cycle

Overflow incontinence → residual urine → bacterial colonisation → UTI → mucosal inflammation → worsened detrusor overactivity → more urgency/frequency → worsened incontinence. The UTI makes the incontinence worse, and the incontinence perpetuates the UTI. Breaking the cycle requires addressing the root cause (relieving obstruction or ensuring regular bladder emptying via CISC).

Mechanism	Pathophysiology
Stagnant residual urine	Urinary stasis → supersaturation of dissolved solutes → crystallisation → stone formation. This is the same principle as stone formation anywhere in the urinary tract — stasis promotes precipitation.
Chronic catheterisation	Catheter acts as a nidus for encrustation and stone formation; biofilm facilitates mineral deposition
Infection	Urease-producing organisms (especially Proteus mirabilis) split urea → ammonia + CO₂ → alkalinise urine → struvite (magnesium ammonium phosphate) stone formation

BPH complications: ↑ residual urine, causing infection and stone ^[6]

This is the most dangerous complication — and it occurs specifically in:

Overflow incontinence from chronic retention (BOO or DUA)
Detrusor-sphincter dyssynergia (DSD) in neurogenic bladder

Mechanism	Pathway	Result
Chronic retention / high-pressure bladder	Persistently elevated intravesical pressure → transmitted retrograde to ureters → vesicoureteral reflux → hydronephrosis → compression of renal parenchyma → tubular and glomerular damage	Obstructive uropathy → renal failure ^[6]
DSD (suprasacral SCI)	Synchronous contraction of detrusor and sphincters → very high intravesical pressure → upper tract damage ^[8] → reflux nephropathy ^[8]	Progressive bilateral hydronephrosis → CKD → ESRD if untreated

BPH complications — Upper tract: recurrent hydronephrosis, obstructive uropathy, renal failure ^[6]

Post-renal AKI can result from bilateral ureteric obstruction or bladder outlet obstruction with high back-pressure. Post-renal AKI due to obstructive uropathy: BPH, CA prostate, bladder neck tumour, urinary stones, UTI ^[22]

When Does Overflow Incontinence Become a Medical Emergency?

When you find: (1) elevated creatinine suggesting obstructive nephropathy, (2) bilateral hydronephrosis on imaging, (3) hyperkalaemia. This means the back-pressure has caused post-renal AKI. Immediate catheterisation is essential and may be life-saving. After catheterisation, watch for post-obstructive diuresis (see below).

When overflow incontinence is caused by acute or chronic retention, the act of relieving the retention itself can cause complications:

Anticipate complications of AROU ^[13]:

Complication	Mechanism	Clinical Features	Management
Post-obstructive diuresis (POD) ^[13]^[6]	Tubular damage → ↓ concentrating ability → rapid fluid and solute loss ^[13]. Also physiological — the body tries to excrete accumulated urea, sodium, and water that built up during the period of obstruction.	UO > 200 mL/h for ≥ 2 hours ^[13] or > 3L in 24 hours. Risk of hypovolaemia, hyponatraemia, hypokalaemia ^[13].	Close monitoring of I/O, fluid/electrolyte status with appropriate replacement and resuscitation (prefer oral hydration, aim to replace 1/2 of UO in the past hour) ^[13]. Chart urine output every 2 hours.
Haemorrhage ex-vacuo ^[13]^[6]	Bladder mucosal disruption with sudden emptying of greatly distended bladder ^[13] — decompression removes tamponade effect → previously compressed mucosal vessels bleed	Transient haematuria following catheterisation	Usually self-limiting, rarely significant ^[13]. Continuous bladder irrigation if persistent.
Transient hypotension ^[13]	Vasovagal response to rapid decompression; relief of pelvic venous congestion → pooling of blood	Hypotension, bradycardia immediately after catheterisation	Trendelenburg position, IV fluids if needed. Some centres advocate gradual decompression (clamping catheter intermittently) but evidence for this is weak.

These are often under-recognised but profoundly affect patient outcomes:

Complication	Mechanism / Why
Depression and anxiety	Embarrassment, loss of dignity, fear of leakage in public, social withdrawal. Studies show UI is an independent risk factor for depression in the elderly.
Social isolation	Fear of incontinence episodes → avoidance of social activities, outings, exercise. She had restricted herself from going out ^[4] — the theme case patient explicitly describes social restriction.
Sexual dysfunction	Fear of leakage during intercourse → avoidance of sexual activity; vaginal atrophy (shared risk factor); coexisting prolapse.
Reduced quality of life	Affects all domains: physical (pad changes, hygiene), emotional (embarrassment, anxiety), social (isolation), occupational (difficulty at work). Although not life-threatening, they can affect the quality of life of a woman ^[3].
Sleep disturbance	Nocturia → fragmented sleep → daytime fatigue, cognitive impairment, increased fall risk
Carer burden	Incontinence is one of the leading reasons for institutionalisation of elderly patients. Carer burnout from frequent toileting assistance, pad changes, laundry.

Patients usually do not volunteer incontinence symptoms due to embarrassment, accepting it as part of normal ageing and childbirth, not being aware that treatment is available, symptom not troublesome enough ^[18]

Mechanism	Why
Rushing to toilet (urgency)	Patients with urge UI feel sudden compelling need to void → hurry → slip and fall
Nocturia	Getting up at night in poor lighting → trip hazards → falls → hip fractures (especially in osteoporotic elderly women)
Wet floor	Urine on the floor from incontinence episodes → slippery surface

UI is an independent risk factor for falls in the elderly. Nocturia ≥ 2 times per night doubles the risk of falls. This is particularly dangerous in the geriatric population where falls → fractures → immobility → further deconditioning → worsened incontinence (a devastating downward spiral).

2. Complications of Treatment

Treatment	Complication	Mechanism
Pads / containment devices	Skin maceration, contact dermatitis, secondary infection	Prolonged moisture exposure; friction from pad material
Vaginal pessary	Erosion into vaginal wall, vaginal discharge, UTI, ulceration, rarely fistula (vesicovaginal or rectovaginal)	Foreign body reaction; pressure necrosis if ill-fitting or not changed regularly. Foreign body, change every 4 to 6 months ^[4]
Excessive fluid restriction	Concentrated urine → bladder irritation → worsening urgency; also dehydration in elderly	Over-zealous response to fluid advice

Drug	Key Complications	Mechanism
Anticholinergics (oxybutynin, solifenacin)	Dry mouth, dry eye, constipation, cognitive impairment ^[6]; urinary retention; tachycardia; blurred vision; acute angle-closure glaucoma	Muscarinic receptor blockade (M1 = cognition; M2 = cardiac; M3 = salivary, lacrimal, GI, detrusor, ciliary)
Mirabegron	Elevated BP ( > 10%) ^[6]; headache; UTI; tachycardia (rare)	β3-agonism on vascular smooth muscle
Duloxetine	Nausea (most common), dizziness, dry mouth, hepatotoxicity (rare)	Serotonin/noradrenaline reuptake inhibition
Desmopressin	Hyponatraemia (potentially life-threatening in elderly); fluid overload	Excessive water reabsorption; exacerbated if combined with thiazides, SSRIs
Topical oestrogen	Vaginal bleeding/spotting (especially early); breast tenderness	Oestrogenic stimulation of atrophic endometrium
Alpha-blockers (for BPH/overflow)	Orthostatic hypotension, nasal congestion, dizziness, retrograde ejaculation (selective α1A blockers)	α1 blockade on vascular smooth muscle; retrograde ejaculation from relaxation of bladder neck
5ARI (finasteride, dutasteride)	Erectile dysfunction (10%), gynaecomastia ^[6]; depression (rare)	↓ DHT → ↓ androgenic effects on prostate but also on androgen-dependent tissues elsewhere

2.3 Complications of Surgical Treatment

Complication	Mechanism	Frequency
Mesh erosion (into vagina, urethra, or bladder)	Foreign body reaction to synthetic polypropylene mesh; tissue ischaemia under mesh → necrosis → exposure	Variable (1-5%); significant medicolegal and regulatory concern in recent years
Bladder perforation (intraoperative)	Trocar passes through bladder wall during retropubic passage (TVT > TOT)	TVT: 3-5%; mandatory intraoperative cystoscopy to detect
Voiding difficulty / retention	Tape placed too tight → excessive urethral compression → inability to void	2-5%; may need tape loosening or division
De novo urgency	Altered urethral dynamics → irritation; or pre-existing occult OAB unmasked	5-15%
Groin pain (TOT > TVT)	Tape passes through obturator muscles and foramen	Usually transient; rarely persistent
Infection	Surgical site or mesh infection	Rare but may require mesh explantation

Complication	Mechanism
De novo urgency (10-20%)	Altered bladder neck position
Voiding difficulty	Over-correction of bladder neck position
Enterocele formation	Shifting the anterior support → posterior compartment weakens
Longer recovery	Open abdominal procedure

Complication	Mechanism
Migration of injected material	Material not fixed in place → tracks along tissue planes
Short durability (need re-injection)	Material absorbed or displaced over time
UTI	Instrumentation, incomplete emptying
Urinary retention	Over-injection → excessive narrowing of lumen

Complication	Mechanism
Mechanical failure (device malfunction)	Hydraulic system has finite lifespan (~10 years)
Erosion (cuff into urethra)	Constant pressure on urethral tissue → ischaemia → necrosis
Infection (requires explantation)	Foreign body implant; biofilm formation
Urethral atrophy	Chronic compression → tissue thinning → recurrent incontinence

Complication	Mechanism
Urinary retention (most important)	Over-suppression of detrusor contractility → patient cannot void → need CISC
UTI	Instrumentation + retention
Haematuria	Cystoscopic needle injection → mucosal trauma
Temporary effect wears off	Botulinum toxin effect lasts 6-9 months → symptoms recur

These are relevant when TURP is performed for BPH causing overflow incontinence:

Complication	Mechanism	Details
TUR syndrome ^[6]^[16]	Dilutional hypoNa + fluid overload + glycine toxicity	S/S: nausea (1st), confusion, cerebral oedema, visual disturbance. Mx: stop OT, Na replacement, Lasix. Prevention: use bipolar (NS irrigant), limit volume < 1L, irrigation pressure < 60 mmHg, limit OT time < 1h ^[16]
Retrograde ejaculation ^[6]^[16]	Incompetent bladder neck → retrograde flow of semen ^[16]	40-60% ^[16] to 70-80% ^[6] — most common long-term complication. Counsel regarding fertility implications.
Incontinence ^[6]^[16]	Urge (early): detrusor irritability from surgical trauma. Stress (late): sphincter damage	1-2% ^[6]^[16]
Urethral stricture / bladder neck stenosis ^[16]	Thermal injury or instrumentation trauma → fibrosis → scarring → stenosis	7-8% ^[16]
Bleeding ^[6]	Ruptured prostatic vessels, coagulopathy	3-7% require transfusion; clot retention may occur
Perforation ^[6]	Resectoscope through prostatic capsule or bladder dome	Can form fistula
Erectile dysfunction ^[16]	Uncommon — cautery near neurovascular bundles	5% ^[16]
Recurrence of BPH ^[16]	Incomplete resection or regrowth of prostatic tissue	5% need re-operation in 5 years ^[16]

Long-term catheterisation: risk of UTI/urosepsis, trauma, stones, urethral strictures, prostatitis, and SCC of bladder ^[13]

Complication	Mechanism
CAUTI and urosepsis	Biofilm formation on catheter → ascending infection → bacteraemia. Risk ↑ 3-7% per catheter-day. Most common cause of nosocomial UTI.
Catheter encrustation and blockage	Mineral deposits (especially struvite in alkaline urine from urease-producing organisms) encrust the catheter → blocks drainage
Bladder stones	Same encrustation process → stone formation around catheter tip
Urethral trauma and stricture	Chronic pressure from catheter on urethral mucosa → erosion, inflammation, fibrosis → stricture (especially at the penoscrotal junction in males)
Bladder spasms	Catheter tip irritates trigone → reflex detrusor contractions → painful spasms and bypassing of urine around catheter
SCC of bladder	Chronic irritation and inflammation from the catheter → squamous metaplasia of urothelium → increased risk of squamous cell carcinoma. Risk becomes significant after > 10 years of catheterisation.
Paraphimosis (males)	Foreskin retracted during catheter insertion and not replaced → oedema → unable to return foreskin → vascular compromise of glans

Type of UI	Key Complications
Stress UI	Skin irritation (if severe), social/psychological impact, UTI (from perineal wetness); complications mostly from treatment (mesh erosion, retention after sling)
Urge UI	Falls (rushing to toilet), nocturia-related falls, sleep disturbance, social isolation; drug complications (anticholinergic cognitive effects in elderly)
Overflow UI	UTI, bladder stones, obstructive uropathy ^[2]; post-obstructive diuresis after decompression; renal failure; complications of long-term catheterisation
Functional UI	Pressure ulcers, skin breakdown, UTI, falls, social dependency, carer burnout, institutionalisation
Continuous UI (fistula)	Severe IAD, social devastation, vaginal infections; complications of surgical repair (recurrence, vesicovaginal fistula recurrence rate 5-15%)
Neurogenic (DSD)	Upper tract damage (most dangerous) ^[8], reflux nephropathy, autonomic dysreflexia (if SCI above T6), recurrent UTI, bladder stones

High Yield Summary

Complications of UI itself:

Dermatological: Incontinence-associated dermatitis, secondary Candida infection, pressure ulcers
Urological: Recurrent UTI (stagnant urine, perineal contamination, catheter-related), bladder stones, obstructive uropathy → renal failure (most dangerous — especially in overflow and DSD)
Psychological/Social: Depression, anxiety, social isolation, sexual dysfunction, sleep disturbance, carer burden
Falls/Fractures: Rushing to toilet (urgency), nocturia in dark, wet floors — UI is an independent risk factor for falls

Complications of retention decompression: Post-obstructive diuresis (UO > 200 mL/h for ≥ 2h — monitor I/O, replace 1/2 of UO), haemorrhage ex-vacuo (transient, self-limiting), transient hypotension

Complications of treatment:

Anticholinergics: Dry mouth, dry eyes, constipation, cognitive impairment (avoid oxybutynin in elderly), retention
Mirabegron: Hypertension
Mid-urethral sling: Mesh erosion, bladder perforation (TVT), voiding difficulty, de novo urgency
TURP: TUR syndrome (hypoNa + glycine toxicity), retrograde ejaculation (40-80%), urethral stricture, incontinence (1-2%)
Long-term catheter: CAUTI, stones, urethral stricture, bladder SCC ( > 10 years)
Botox: Urinary retention (need CISC capability)

Most dangerous complications to remember: Upper tract damage/renal failure (overflow, DSD), TUR syndrome (post-TURP), hyponatraemia (desmopressin), CAUTI/urosepsis (catheter)

Active Recall - Complications of Urinary Incontinence

References

^[2] Senior notes: Ryan Ho Urogenital.pdf (p159, p161) ^[3] Lecture slides: Block C - O&G Theme Case 4.pdf (p1); GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p74) ^[4] Lecture slides: Block C - O&G Theme Case 4.pdf (p3, p5) ^[6] Senior notes: Maksim Surgery Notes.pdf (p309, p316, p318) ^[8] Senior notes: Ryan Ho Neurology.pdf (p53) ^[13] Senior notes: Ryan Ho Fundamentals.pdf (p352, p353) ^[16] Senior notes: Ryan Ho Urogenital.pdf (p177); Maksim Surgery Notes.pdf (p317) ^[18] Lecture slides: GC 116. I felt a lump below urinary incontinence in females; genital prolapse.pdf (p73) ^[19] Senior notes: Ryan Ho Rheumatology.pdf (p118) — incontinence-associated ICD ^[20] Senior notes: Maksim Medicine Notes.pdf (p192) ^[21] Senior notes: Ryan Ho Endocrine.pdf (p98) ^[22] Senior notes: Ryan Ho Critical Care.pdf (p25)

High Yield Summary

Definition: Urinary incontinence (UI) is the complaint of any involuntary leakage of urine. It is common, increases with age, but is not normal ageing.

Continence depends on pelvic floor support, intrinsic urethral closure, intact sphincters, and coordinated neurological control from cortex -> pontine micturition centre -> sacral cord.

Female risk factors: Vaginal childbirth, menopause/oestrogen deficiency, obesity, chronic cough, chronic constipation, diabetes mellitus, age, and prior pelvic surgery.

Types of UI:

Stress UI: Leakage on cough, sneeze, exertion; due to urethral hypermobility or intrinsic sphincter deficiency.
Urge UI/OAB: Leakage with urgency; usually detrusor overactivity.
Overflow UI: Chronic retention with dribbling; due to BOO or detrusor underactivity.
Functional UI: Cognitive/mobility/environmental barrier to toileting.
Continuous UI: Fistula or ectopic ureter bypassing continence mechanism.
Mixed UI: Most often stress + urge symptoms.

Transient causes — DIAPPERS: Delirium, Infection, Atrophic urethritis/vaginitis, Pharmaceuticals, Psychological, Excess urine output, Restricted mobility, Stool impaction.

POP link: POP and stress UI share weak pelvic floor support. Severe prolapse may mask occult SUI by kinking the urethra.

High Yield Summary — DDx and Diagnosis

DDx framework: First rule out transient causes, then classify the incontinence type by history, then identify the underlying cause.

Clinical clues:

Stress UI: triggered by cough/sneeze/exercise, small-volume leakage, no urgency.
Urge UI: urgency, frequency, nocturia, key-in-lock/running-water triggers.
Overflow UI: hesitancy, weak stream, incomplete emptying, palpable bladder, high PVR.
Continuous UI: constant wetness despite normal voiding.
Functional UI: patient recognises need but cannot reach/use toilet in time.

Terminology pitfall:

Clinical stress UI is symptom-based.
Urodynamic stress incontinence (USI) is leakage during filling cystometry with increased abdominal pressure and no detrusor contraction.
OAB/UUI is symptom-based; detrusor overactivity is urodynamic.

Basic investigations for all: Urinalysis/urine C/ST, bladder diary for at least 3 days, post-void residual by bladder scan, RFT, and glucose.

Useful tests:

Cough stress test: demonstrates stress leakage.
Uroflowmetry: screens for BOO but cannot distinguish BOO from detrusor underactivity.
Urodynamics: gold standard; filling phase diagnoses USI/DO, voiding phase distinguishes BOO from DUA.
Pelvic ultrasound/TVUS: when pelvic mass, prolapse, or gynae pathology is suspected.

Red flags: Cauda equina symptoms need urgent MRI and decompression. High-pressure neurogenic bladder/DSD risks upper tract damage.

High Yield Summary — Management

Universal first steps: Treat DIAPPERS causes, review drugs, optimise fluid intake, reduce caffeine, lose weight, stop smoking, treat constipation/cough, and manage diabetes.

Stress UI ladder:

Pelvic floor muscle training +/- biofeedback for at least 15-20 weeks.
Adjuncts such as topical vaginal oestrogen for atrophy; duloxetine where appropriate/available.
Surgery if conservative treatment fails: mid-urethral sling (TVT/TOT) is the main surgical option; alternatives include Burch colposuspension, bulking agents, or autologous sling.

Urge UI/OAB ladder:

Bladder training, urgency suppression, PFMT, lifestyle measures.
Anticholinergics or beta-3 agonist such as mirabegron.
Botox, sacral neuromodulation, or augmentation cystoplasty in refractory cases.

Medication cautions:

Anticholinergics: dry mouth, constipation, cognitive impairment, urinary retention; avoid/caution with high PVR, narrow-angle glaucoma, dementia.
Mirabegron: can raise blood pressure; avoid in severe uncontrolled hypertension.

Overflow UI:

BOO: relieve obstruction, e.g. alpha-blocker +/- 5ARI in men; TURP if indicated.
Detrusor underactivity: clean intermittent self-catheterisation is the gold standard.

POP + UI: Ring pessary + PFMT first; if surgery is planned, test for occult SUI with the prolapse reduced and consider combined prolapse + anti-incontinence surgery.

High Yield Summary — Complications

Complications of UI itself:

Skin: incontinence-associated dermatitis, Candida, pressure ulcers.
Urological: recurrent UTI, bladder stones, chronic retention, hydronephrosis, obstructive uropathy/renal failure.
Psychosocial: embarrassment, isolation, depression, sexual dysfunction, carer burden.
Falls/fractures: urgency, nocturia, rushing to the toilet, wet floors.

Retention decompression complications: Post-obstructive diuresis, haematuria ex vacuo, transient hypotension. Monitor input/output and electrolytes after large-volume catheter drainage.

Treatment complications:

Anticholinergics: cognitive impairment and retention are especially important in older patients.
Mid-urethral sling: bladder perforation, mesh erosion, voiding difficulty, de novo urgency.
Botox: urinary retention; patient must be willing/able to catheterise if needed.
Long-term catheter: CAUTI, stones, urethral trauma/stricture, bladder SCC after prolonged use.
TURP: TUR syndrome, retrograde ejaculation, urethral stricture, incontinence.

Most dangerous patterns: Overflow retention and detrusor-sphincter dyssynergia can cause upper tract damage and renal failure.

Urinary Incontinence

1. Definition

2. Epidemiology

3. Risk Factors

Female-specific risk factors (heavily emphasised in lectures):

General risk factors (both sexes):

Male-specific risk factors:

4. Anatomy and Function of the Continence Mechanism

4.1 The Pelvic Floor

4.2 Mechanisms of Continence

4.3 Neural Control of Micturition

The micturition reflex arc:

Key neural pathways:

Patterns of neurological bladder dysfunction:

5. Aetiology and Pathophysiology

5.1 Classification of Urinary Incontinence by Type

5.1.1 Stress Urinary Incontinence (SUI)

5.1.2 Urge Urinary Incontinence (UUI)

5.1.3 Mixed Incontinence

5.1.4 Overflow Incontinence

5.1.5 Functional Incontinence

5.1.6 Continuous Incontinence (Structural)

5.2 Transient / Reversible Causes

5.3 Drug Causes of Urinary Incontinence

6. Classification

6.1 By Mechanism (Most Clinically Useful)

6.2 By Duration

7. Clinical Features

7.1 Symptoms (with pathophysiological basis)

7.2 Signs (with pathophysiological basis)

General Examination:

Abdominal Examination:

Vaginal Examination (Critical in Females):

DRE (Digital Rectal Examination):

Neurological Examination:

8. Association Between Pelvic Organ Prolapse and Urinary Incontinence

9. Special Considerations in the Hong Kong Context

Active Recall - Urinary Incontinence

References

1. The First Step: Is It Transient or Established?

2. Differentiating the Type of Incontinence

3. Differential Diagnosis by Type — Underlying Aetiologies

3.1 Stress Urinary Incontinence — DDx of Causes

3.2 Urge Urinary Incontinence — DDx of Causes

3.3 Overflow Incontinence — DDx of Causes

3.4 Functional Incontinence — DDx of Causes

3.5 Continuous Incontinence — DDx of Causes

4. Special Differential Diagnostic Scenarios

4.1 The Elderly Woman with Prolapse and Incontinence

4.2 The Man with LUTS and Incontinence

4.3 Neurological Causes — Thinking by Level

5. Differential Diagnosis Algorithm

6. Putting It All Together — A Systematic DDx Table

7. History Clues That Point to Specific Diagnoses

Active Recall - Differential Diagnosis of Urinary Incontinence

1. Diagnostic Criteria

1.1 Clinical Diagnostic Criteria (Symptom-Based)

1.2 Urodynamic Diagnostic Criteria

1.3 The Hald Diagram — Understanding the Diagnostic Overlap

2. Diagnostic Algorithm

3. Investigation Modalities — Detailed Breakdown

3.1 Bedside / First-Line Investigations

3.1.1 Bladder Diary (Frequency-Volume Chart)

3.1.2 Urinalysis and Urine C/ST

3.1.3 Post-Void Residual Volume (PVR)

3.1.4 Cough Stress Test (Provocation Test)

3.1.5 Pad Test

3.2 Blood Investigations

3.3 Symptom Scores

3.4 Uroflowmetry

3.5 Urodynamic Studies (Gold Standard)

3.6 Cystoscopy

3.7 Imaging

4. Special Investigation Scenarios

4.1 The Theme Case Approach (Mrs. Wong) [4]

4.2 Assessment of Prolapse with Incontinence

4.3 When Neurological Cause Is Suspected

5. Summary Table: Which Investigation for Which Question?

Active Recall - Diagnosis and Investigation of Urinary Incontinence

1. General Principles