# Urinary Incontinence: Evaluation and Treatment

## Overview

Urinary incontinence is the involuntary loss of urine that is objectively demonstrable and constitutes a social or hygienic problem. It affects 25 to 50% of adult women, with prevalence increasing with age. It is significantly underreported, as only 25 to 50% of affected women seek medical care. The condition has a major impact on quality of life, sexual function, and psychological well-being.

## Types of Urinary Incontinence

### Stress Urinary Incontinence (SUI)

Stress urinary incontinence is involuntary leakage that occurs with effort, exertion, sneezing, or coughing. It is the most common type in younger women under 60 years of age. The pathophysiology involves urethral hypermobility and/or intrinsic sphincter deficiency. Urethral hypermobility occurs when a weakened pelvic floor allows the bladder neck to descend during increased abdominal pressure. Intrinsic sphincter deficiency represents poor urethral coaptation and is associated with prior surgery, radiation, or neurologic injury.

### Urgency Urinary Incontinence (UUI)

Urgency urinary incontinence is involuntary leakage accompanied by or immediately preceded by a sensation of urgency. It is more common in older women and is a component of overactive bladder syndrome. The underlying pathophysiology is detrusor overactivity, in which involuntary detrusor contractions occur during the filling phase.

### Mixed Urinary Incontinence (MUI)

Mixed urinary incontinence is a combination of stress and urgency incontinence and is very common, affecting 30 to 40% of incontinent women. Treatment should target the predominant symptom first.

### Other Types

Overflow incontinence involves continuous leakage from an overdistended bladder and results from neurogenic bladder, obstruction, or detrusor underactivity. Functional incontinence occurs when cognitive or physical limitations prevent the patient from reaching the toilet. Continuous incontinence, meaning constant leakage, should raise suspicion for a fistula (vesicovaginal or ureterovaginal) or an ectopic ureter.

| Type | Mechanism | Key Feature | Treatment Focus |
|---|---|---|---|
| Stress (SUI) | Urethral hypermobility / ISD | Leakage with cough, sneeze, exertion | PFMT, midurethral sling |
| Urgency (UUI) | Detrusor overactivity | Leakage preceded by urgency | Bladder training, antimuscarinics/beta-3 agonists |
| Mixed (MUI) | Combined SUI + UUI | Both stress and urgency components | Treat predominant symptom first |
| Overflow | Detrusor underactivity / obstruction | Continuous leakage, high PVR | CIC, treat underlying cause |
| Continuous | Fistula or ectopic ureter | Constant leakage | Surgical repair |

## Evaluation

### History

A thorough history should characterize the type and severity of leakage, distinguishing between stress and urgency components. Frequency, nocturia, and pad use should be documented. Fluid intake habits, particularly caffeine, alcohol, and total volume, are relevant. A 3- to 7-day voiding diary documenting fluid intake, voiding frequency, volume, incontinence episodes, and associated activities is one of the most useful diagnostic tools. Quality-of-life impact can be quantified using validated questionnaires such as the UDI-6, IIQ-7, or PFDI-20. Obstetric and surgical history, medications (diuretics, ACE inhibitors, alpha-blockers, anticholinergics), neurologic symptoms, and prior incontinence treatments should all be explored.

### Physical Exam

The cough stress test is performed with the bladder filled to 200 to 300 mL, observing for leakage with coughing in the lithotomy and/or standing position. Immediate leakage with cough indicates SUI, while delayed leakage may indicate a triggered detrusor contraction (UUI). Pelvic organ prolapse is assessed using the POP-Q system. The Q-tip test involves inserting a cotton-tipped swab into the urethra; deflection greater than 30 degrees with straining suggests urethral hypermobility. Pelvic floor muscle strength, vaginal atrophy, and a neurologic exam including perineal sensation, anal wink, and the bulbocavernosus reflex should all be assessed.

### Basic Workup

Urinalysis and urine culture rule out urinary tract infection or hematuria. Post-void residual measurement is important, as an elevated PVR above 150 to 200 mL suggests retention or overflow incontinence. A voiding diary should always be obtained.

### Advanced Testing: Urodynamics

Urodynamics is not required for all patients, and many can be treated empirically based on clinical evaluation. Indications for urodynamics include an uncertain diagnosis after clinical evaluation, failed initial treatment, prior anti-incontinence surgery, planned surgical intervention (to confirm the diagnosis preoperatively), suspected neurogenic bladder, and mixed incontinence with an unclear predominant type. Components include uroflowmetry to measure voiding flow rate and pattern, cystometry to assess detrusor pressure during filling (detecting uninhibited contractions indicating UUI), pressure-flow studies during the voiding phase, Valsalva leak point pressure (VLPP, where less than 60 cm H2O suggests intrinsic sphincter deficiency), and urethral pressure profile.

<image>Urodynamic tracing showing cystometry with filling phase demonstrating a stable detrusor (normal) versus detrusor overactivity with involuntary contractions during filling causing urgency and leakage, alongside stress testing showing increased abdominal pressure with leak (positive stress test for SUI)</image>

## Conservative Management (First-Line for All Types)

### Behavioral Strategies

Bladder training uses timed voiding with gradual increases in voiding intervals, starting at the current interval and increasing by 15 to 30 minutes weekly, with a goal of 3 to 4 hours between voids. Pelvic floor muscle training (Kegels) involves 3 sets of 10 to 15 contractions daily. Supervised physical therapy is more effective than self-guided exercises. PFMT is effective for SUI, reducing episodes by 50 to 80%, and also benefits UUI. It requires 6 to 12 weeks for benefit. Biofeedback serves as an adjunct to PFMT. Electrical stimulation using intravaginal or surface electrodes can strengthen the pelvic floor. Weight loss of 5 to 10% reduces SUI episodes by 50%, as demonstrated by the PRIDE study.

### Lifestyle Modifications

Reducing caffeine and alcohol intake, moderating fluid consumption (without excessive restriction), smoking cessation (since chronic cough exacerbates SUI), managing chronic constipation, and learning urge suppression techniques (distraction, relaxation, and pelvic floor contraction when the urge occurs) are all beneficial.

### Continence Devices

An incontinence pessary, either a ring or dish type, can be placed to support the bladder neck for SUI. Over-the-counter urethral inserts such as the Impressa are intravaginal devices that support the urethra during exercise. Incontinence pads and protective garments provide symptom management.

## Pharmacotherapy

### For Urgency Urinary Incontinence / OAB

Antimuscarinics (anticholinergics) include oxybutynin (immediate and extended release), tolterodine, solifenacin, darifenacin, fesoterodine, and trospium. They work by blocking muscarinic M3 receptors on the detrusor muscle. Side effects include dry mouth (the most common), constipation, blurred vision, cognitive impairment (especially in elderly patients), and urinary retention. Extended-release and transdermal formulations have fewer side effects. Caution is warranted in elderly patients, as the anticholinergic burden increases dementia risk according to the AGS Beers criteria.

Beta-3 agonists include mirabegron at 25 to 50 mg daily and vibegron at 75 mg daily. They relax the detrusor through beta-3 adrenergic receptors. They have a better cognitive safety profile than anticholinergics and are preferred in elderly patients. They should be avoided in uncontrolled hypertension. They can be combined with an antimuscarinic for refractory cases.

Vaginal estrogen improves urogenital atrophy and may reduce UUI symptoms. It serves as an adjunct to other therapies.

### For Stress Urinary Incontinence

Duloxetine, an SNRI, increases urethral sphincter tone via pudendal nerve activation. It is used in some countries for SUI but is not FDA-approved for this indication in the United States. Topical vaginal estrogen may improve periurethral tissue and mild SUI. There is no highly effective pharmacologic option for SUI; surgery remains the definitive treatment.

<image>Comparison table of pharmacologic treatments for urinary incontinence: antimuscarinics (oxybutynin, solifenacin, etc.) with mechanism, dosing, and side effects listed; beta-3 agonists (mirabegron, vibegron) with advantages over anticholinergics; and adjunct therapies including topical vaginal estrogen, organized by incontinence type</image>

## Surgical Management of Stress Urinary Incontinence

### Midurethral Sling (MUS)

The midurethral sling is the gold standard surgical treatment for SUI. A polypropylene mesh tape is placed at the mid-urethra. The retropubic approach (TVT) passes the tape retropubically and may offer slightly higher efficacy for intrinsic sphincter deficiency. The transobturator approach (TOT) passes the tape through the obturator foramen and has a lower risk of bladder perforation. Outcomes show 80 to 90% cure or improvement at 5 years. Complications include mesh erosion or exposure (2 to 5%), voiding dysfunction, bladder perforation (with the retropubic approach), groin pain (with the transobturator approach), and de novo urgency. Intraoperative cystoscopy is mandatory after retropubic sling placement. It is important to recognize that midurethral slings are distinct from transvaginal mesh for prolapse repair (which was removed from the market); midurethral slings remain available and are supported by strong evidence.

### Burch Colposuspension

Burch colposuspension, performed open or laparoscopically, involves suturing paravaginal tissue to Cooper ligament (the iliopectineal line). It was historically the gold standard before midurethral slings and has similar efficacy to the retropubic MUS. It can be performed at the time of sacrocolpopexy for concurrent prolapse and SUI.

### Autologous Fascial Sling (Pubovaginal Sling)

This procedure uses the patient's own fascia (rectus fascia or fascia lata) placed at the bladder neck. It is used for intrinsic sphincter deficiency, recurrent SUI after a failed mesh sling, or situations where mesh is contraindicated. It has higher voiding dysfunction rates but excellent long-term durability.

### Urethral Bulking Agents

Injection of bulking material (polyacrylamide hydrogel or calcium hydroxylapatite) around the urethra is an office-based, minimally invasive procedure. Efficacy is lower than sling surgery at 50 to 60% improvement, and multiple injections may be needed. It is reserved for patients who are poor surgical candidates or prefer a minimally invasive option.

## Surgical Management of Urgency Urinary Incontinence (Refractory)

### Sacral Neuromodulation (InterStim)

An implanted neurostimulator modulates the S3 sacral nerve root. The procedure is performed in two stages: a test phase with staged lead placement followed by permanent implant. Efficacy shows 70 to 80% improvement, with 45 to 50% achieving full continence. It is also effective for non-obstructive urinary retention and fecal incontinence. Current devices are MRI-compatible.

### Posterior Tibial Nerve Stimulation (PTNS)

A percutaneous needle electrode is placed near the medial ankle to stimulate the posterior tibial nerve. Weekly 30-minute sessions for 12 weeks are followed by monthly maintenance. It is a non-invasive alternative to sacral neuromodulation with efficacy similar to anticholinergics.

### OnabotulinumtoxinA (Botox)

Injection of 100 to 200 units into the detrusor muscle via cystoscopy is effective for refractory UUI, with 70 to 80% improvement. The duration of effect is 6 to 12 months, requiring repeat injections. The main risk is urinary retention requiring self-catheterization, occurring in 5 to 10% of patients.

## Clinical Pearls

A voiding diary is the single most useful tool for distinguishing SUI from UUI and guiding treatment. Always obtain one before initiating therapy.

Pelvic floor muscle training is effective for both SUI and UUI and should be offered as first-line treatment before medications or surgery.

Weight loss of 5 to 10% reduces SUI episodes by 50%. This modifiable risk factor should be emphasized.

Anticholinergics should be used cautiously in elderly patients due to cognitive side effects. Beta-3 agonists (mirabegron, vibegron) are preferred in this population.

Midurethral slings remain the gold standard surgery for SUI. They are distinct from transvaginal mesh for prolapse repair and have strong safety data.

Always perform a cough stress test with prolapse reduced before prolapse surgery to identify occult SUI that may need concurrent treatment.

Post-void residual should be checked before starting anticholinergic therapy and in any patient with voiding difficulty.

## References

- ACOG Practice Bulletin No. 155: Urinary Incontinence in Women (2015, reaffirmed 2023)
- AUA/SUFU Guideline: Diagnosis and Treatment of Non-Neurogenic Overactive Bladder in Adults (2019, amended 2023)
- Ford AA et al. Mid-urethral sling operations for stress urinary incontinence in women. Cochrane Database Syst Rev. 2017
- Subak LL et al. (PRIDE study). Weight loss to treat urinary incontinence in overweight and obese women. N Engl J Med. 2009;360:481-490
- Dumoulin C et al. Pelvic floor muscle training versus no treatment for urinary incontinence in women. Cochrane Database Syst Rev. 2018
- Nambiar AK et al. EAU Guidelines on Assessment and Nonsurgical Management of Urinary Incontinence. Eur Urol. 2018;73:596-609