Key Facts

Urinary incontinence is a common and often underreported condition that significantly impacts quality of life. Systematic assessment, conservative management, and appropriate escalation to pharmacological or surgical treatment are essential.

Epidemiology

• Prevalence: 25-40% of adult women; increases with age
• SUI: most common type in younger women; UUI more common in older women
• Mixed incontinence: combination of SUI and UUI in approximately 30% of cases
• Only 25-50% of affected women seek medical help

Aetiology

• SUI: weakness of pelvic floor support and/or urethral sphincter; causes include vaginal delivery, pelvic surgery, menopause (oestrogen deficiency), obesity, chronic straining
• UUI/OAB: detrusor overactivity (involuntary detrusor contractions); may be idiopathic, neurogenic (stroke, MS, Parkinson disease, spinal cord injury), or due to bladder pathology (UTI, stones, tumour)
• Overflow incontinence: bladder outlet obstruction or detrusor underactivity
• Functional incontinence: immobility, cognitive impairment

Pathophysiology

• SUI: increased intra-abdominal pressure exceeds urethral closure pressure; weakened pelvic floor and urethral support from childbirth, oestrogen deficiency, connective tissue weakness
• UUI: involuntary detrusor contractions during filling phase; may involve afferent nerve sensitisation, urothelial dysfunction, or myogenic changes

Stress Urinary Incontinence

• Leakage with cough, sneeze, laugh, exercise, or lifting
• No urgency before leakage
• Small-volume leakage
• Reproducible on examination (cough test)

Urgency Urinary Incontinence

• Sudden compelling desire to void followed by involuntary leakage
• Frequency (>8 voids/day)
• Nocturia (≥2 times/night)
• Often moderate-large volume leakage

Red Flags

• Haematuria (exclude bladder cancer)
• Pelvic pain or mass (pelvic pathology)
• Recurrent UTIs
• Voiding difficulty (exclude overflow/obstruction)
• Neurological symptoms (MS, cauda equina)
• Continuous leakage (fistula)

Bedside

• Bladder diary: 3-day diary recording fluid intake, void times, volumes, leakage episodes, pad usage
• Urinalysis and MSU (exclude UTI)
• Cough test (in supine/standing): observe for SUI
• Post-void residual volume (bladder scan): exclude overflow
• Pelvic floor assessment (voluntary contraction strength)
• POP-Q assessment if prolapse suspected

Bloods

• Not routinely required
• U&Es if renal impairment suspected (bilateral hydronephrosis from severe prolapse)
• HbA1c if polyuria/nocturia (exclude diabetes)

Imaging

• Post-void residual USS: if voiding symptoms or suspected overflow
• Renal USS: if recurrent UTIs or suspected upper tract involvement

Special Tests

• Urodynamics: recommended before surgery for SUI, if diagnosis uncertain, or if mixed incontinence with surgical consideration
  • Cystometry: measures detrusor pressure during filling and voiding
  • Identifies detrusor overactivity, low compliance, or voiding dysfunction

Non-pharmacological

• Pelvic floor muscle training (PFMT): first-line for SUI and mixed incontinence; at least 3 months of supervised exercises (8 contractions × 3 times daily); NICE NG123
• Bladder training: first-line for UUI/OAB; scheduled voiding with gradual increase in intervals; at least 6 weeks
• Lifestyle modification: weight loss (5-10% reduces SUI episodes by 50%), reduce caffeine, adequate fluid intake (1.5-2L/day), manage chronic cough, treat constipation
• Vaginal oestrogen: estriol cream/pessaries for postmenopausal women (improves urogenital atrophy)
• Incontinence pads/products as adjunct

Pharmacological

• For UUI/OAB (if bladder training insufficient):
  • Antimuscarinics: oxybutynin 2.5-5mg BD-TDS (or ER 5-10mg OD), solifenacin 5-10mg OD, tolterodine 2mg BD (or ER 4mg OD)
  • Mirabegron 50mg OD: β3-adrenoceptor agonist; fewer anticholinergic side effects; preferred in elderly
  • Caution with antimuscarinics in elderly: cognitive impairment, dry mouth, constipation, blurred vision
• For SUI: duloxetine 40mg BD (SNRI; off-label; limited evidence; not recommended by NICE as routine)

Surgical/Interventional

• For SUI (if conservative management fails):
  • Colposuspension (Burch): laparoscopic or open; gold standard; cure rate 85-90%
  • Autologous fascial sling: using rectus sheath or fascia lata
  • Urethral bulking agents (Bulkamid): injected periurethrally; less invasive; moderate efficacy
  • Mid-urethral tape (TVT/TOT): highly effective (90%); currently under review following mesh complications
  • Artificial urinary sphincter: for severe intrinsic sphincter deficiency
• For refractory UUI/OAB:
  • Botulinum toxin A 200 units injected into detrusor (lasts 6-9 months; risk of retention 5%)
  • Sacral nerve stimulation (SNS): implantable neurostimulator
  • Augmentation cystoplasty: last resort; increases bladder capacity

Referral Criteria

• Failed conservative management after 3-6 months: urogynaecology referral
• Red flag symptoms: urgent urology referral
• Complex or recurrent incontinence: specialist urogynaecology
• Neurological cause suspected: neurology and urology joint management

• PFMT: 50-70% improvement in SUI symptoms with adherence
• Bladder training: 50-80% improvement in OAB symptoms
• Surgical repair for SUI: 85-90% objective cure rate (colposuspension)
• Botox for OAB: 70-80% response rate; repeat injections required
• Incontinence is not an inevitable part of ageing; most women improve with appropriate treatment

NICE NG123 Treatment Pathway

Antimuscarinic Comparison