Urinary Incontinence: Types, Physiology, and Management
Begin with pelvic floor muscle training (PFMT) as first-line therapy for stress urinary incontinence and bladder training for urgency incontinence, as these conservative interventions reduce episodes by more than 50% and should always precede pharmacologic or surgical options. 1, 2
Types and Underlying Physiology
Stress Urinary Incontinence (SUI)
- Involuntary urine leakage during physical activities such as coughing, sneezing, laughing, exercise, or bending, caused by urethral sphincter failure and loss of anatomical urethral support when intra-abdominal pressure increases 1
- Most prevalent type in women, affecting 20-30% of young adults and peaking at 30-50% between ages 45-59 years 1
- Primary mechanism: poorly functioning urethral closure mechanism combined with inadequate pelvic floor support 1
Urgency Urinary Incontinence (UUI)
- Involuntary urine loss accompanied by or immediately preceded by a sudden, compelling urge to void 1, 3
- Related to detrusor muscle overactivity and dysfunction of neural controls for bladder storage 3
- Often part of overactive bladder syndrome (urgency with or without incontinence, frequency, and nocturia) 1
Mixed Urinary Incontinence (MUI)
- Combination of both stress and urgency symptoms, particularly common in older women where distinction becomes less clear 1, 4
Other Types
- Overflow incontinence: bladder becomes too full because it cannot be fully emptied 4
- Functional incontinence: inability to reach toilet due to physical or cognitive impairment 4
- Extraurethral incontinence: urine leakage through abnormal channels 1
Diagnostic Approach
Initial Screening
- Proactively ask all female patients about bothersome urinary symptoms during routine visits, as most women (>50%) do not voluntarily report incontinence 1, 2
- Use specific screening questions: "Do you have a problem with urinary incontinence that is bothersome enough that you would like to know more about treatment?" 1
Focused History Elements
- Time of onset, specific symptom patterns (leakage with cough/sneeze vs. urgency), frequency of episodes, and impact on quality of life 1, 2
- Obstetrical history (vaginal deliveries), gynecologic surgeries (hysterectomy), and risk factors: obesity, chronic cough, constipation, diabetes, smoking, caffeine intake 1
- Medication review and assessment of cognitive/functional status 1
Physical Examination
- Focused neurologic examination to rule out serious underlying pathology 1, 2
- Pelvic examination to assess for pelvic organ prolapse, vaginal atrophy, and pelvic floor muscle function 2
- Cough stress test if stress incontinence suspected: observe for urine leakage with coughing while bladder is full 5
Essential Testing
- Urinalysis to rule out infection and hematuria before initiating treatment 6, 5
- Postvoid residual urine volume measurement to exclude overflow incontinence 5
- Voiding diary (3-7 days) documenting fluid intake, voiding times, volumes, and incontinence episodes 5
- Invasive urodynamics reserved for when initial treatments fail or diagnosis remains unclear 1
Management Algorithm
First-Line: Conservative Management (ALL Patients)
For Stress Urinary Incontinence
- Supervised pelvic floor muscle training (PFMT) is mandatory first-line therapy, taught by a healthcare professional with proper instruction on voluntary pelvic floor muscle contractions (Kegel exercises) 1, 2
- Supervised PFMT is more than 5 times as effective as no treatment (NNT = 2) 2, 7
- Requires adequate trial of minimum 3 months before considering escalation 2
- PFMT with biofeedback using vaginal EMG provides visual feedback for proper muscle contraction technique 1
For Urgency Urinary Incontinence
- Bladder training as primary initial treatment: scheduled voiding with progressively longer intervals between bathroom trips (NNT = 2) 1, 7
- Do NOT add PFMT to bladder training for pure urgency incontinence, as it provides no additional benefit 7
For Mixed Urinary Incontinence
Lifestyle Modifications (All Types)
- Weight loss for obese patients (BMI >30) with strong evidence for symptom reduction 1, 2
- Adequate but not excessive fluid intake, avoidance of bladder irritants (caffeine, alcohol) 2, 6
- Regular voiding intervals to reduce urgency episodes 6
- Address modifiable factors: smoking cessation, treatment of chronic cough, constipation management 1
Second-Line: Pharmacologic Therapy
For Stress Urinary Incontinence
- Do NOT use systemic pharmacologic therapy for stress incontinence—it is ineffective and represents wrong treatment 1, 2, 7
For Urgency Urinary Incontinence (Only After Bladder Training Fails)
- Anticholinergic medications or beta-3 agonists: oxybutynin, tolterodine, darifenacin, solifenacin, fesoterodine, trospium 1, 7
- All agents show similar moderate effectiveness; select based on tolerability, adverse effects, ease of use, and cost rather than efficacy 1, 7
- Oxybutynin exerts direct antispasmodic effect on bladder smooth muscle, inhibits muscarinic action of acetylcholine, increases bladder capacity, and diminishes frequency of uninhibited detrusor contractions 8
- Tolterodine reduces incontinence episodes, micturition frequency, and increases voided volume per micturition 9
- Major adverse effects: dry mouth, constipation, cognitive impairment (especially in elderly)—counsel patients upfront to improve adherence 7
- Poor adherence common due to side effects; reassess symptoms within 4-8 weeks 7, 6
Third-Line: Minimally Invasive and Surgical Options
For Stress Urinary Incontinence (After Conservative Measures Fail)
- Synthetic midurethral slings (MUS) are most common primary surgical treatment with 48-90% symptom improvement and <5% mesh-related complications 1, 6
- Both retropubic and transobturator approaches effective, though concerns about mesh complications have decreased utilization 1
- Single-incision slings (SIS) show promising short-term effectiveness comparable to MUS, but long-term efficacy data still lacking 1
- Urethral bulking agents (UBA) as alternative with different adverse event profile, though generally lower efficacy than slings 1
- Colposuspension (Burch procedure) supported by robust evidence with different complication profile than mesh 1
- Autologous fascial slings (AFS) for complicated/severe SUI or when synthetic mesh contraindicated 1
- Artificial urinary sphincters (AUS) for severe/complicated SUI, though high-quality comparative data lacking 1
For Urgency Urinary Incontinence (Refractory to Medications)
- OnabotulinumtoxinA (Botox) bladder injections for refractory urgency incontinence 6
- Percutaneous or implanted neuromodulators (sacral nerve stimulation) 6
Critical Pitfalls to Avoid
Never Skip Behavioral Interventions
- Always attempt PFMT and/or bladder training first before medications or surgery—no harms identified with behavioral interventions, and they have strong evidence 1, 2, 7
- Minimum 3 months supervised PFMT required before considering surgical intervention 2
Wrong Treatment for Wrong Type
- Never use systemic medications for stress incontinence—completely ineffective 1, 2, 7
- Do not add PFMT to bladder training for pure urgency incontinence—provides no benefit 7
Surgical Contraindications
- Do not use transobturator midurethral slings in patients with fixed/immobile urethras 2
- Avoid synthetic mesh in patients with: poor tissue quality, significant pelvic scarring, radiation history, or concomitant urethral procedures 2
- Cystoscopy is now standard component during surgical sling implantation to detect bladder injury 1
Medication Management Errors
- Set realistic expectations about anticholinergic side effects (dry mouth, constipation, cognitive effects) to prevent early discontinuation 7
- Weigh symptom severity against medication adverse effects—not all patients require pharmacotherapy if behavioral measures provide adequate relief 7
Referral Indications
- Hematuria, obstructive symptoms, recurrent urinary tract infections, or suspected serious neurologic disease 6, 5
- Advanced pelvic organ prolapse requiring concomitant repair 6
- Failure of conservative and medical management 6
- Diagnostic uncertainty after initial evaluation 5
Treatment Success Definition
- Clinically successful treatment reduces urinary incontinence episode frequency by at least 50% 1, 2
- Complete continence is ideal but not always achievable; focus on meaningful quality of life improvement 1
Special Considerations
Complicated/Severe SUI
- Management remains challenging with limited high-quality comparative data 1
- Autologous fascial slings and artificial urinary sphincters are established treatments but require specialist expertise 1
Mesh-Related Concerns
- Notable escalation in invasiveness and complication rates with surgical interventions has created patient hesitance 1
- Mesh complications include erosion, pain, dyspareunia, but rates remain <5% with proper patient selection 6
- Decreased utilization of mesh procedures due to regulatory and medicolegal concerns despite robust efficacy data 1