What are the causes and treatment options for fecal incontinence, or the inability to hold defecation?

Fecal Incontinence: Causes and Treatment

All patients with fecal incontinence must begin with rigorous conservative therapy—including dietary modification, antidiarrheal medications (loperamide starting at 2 mg before breakfast, titrating to 16 mg daily), fiber supplementation, scheduled toileting, and pelvic floor exercises—before considering any surgical or device-based interventions. 1, 2

Definition and Impact

Fecal incontinence is the recurrent uncontrolled passage of liquid or solid stool, affecting 7-15% of community-dwelling adults with higher rates in elderly and institutionalized populations. 1 This condition devastatingly impacts quality of life, causing loss of confidence, self-respect, and social isolation. 1

Primary Risk Factors and Causes

Diarrhea is by far the single most important risk factor, with an odds ratio of 53 compared to other causes. 1, 2 Other significant independent risk factors include:

• Bowel disturbances and rectal urgency (more important than obstetric history in older women) 1
• Cholecystectomy (OR 4.2) 1
• Current smoking (OR 4.7) 1
• History of rectocele (OR 4.9) 1
• Stress urinary incontinence (OR 3.1) 1
• Higher BMI (OR 1.1 per unit increase) 1
• Advanced age, diabetes, anal sphincter trauma (obstetrical injury, prior surgery), decreased physical activity 1
• Neurological disorders (dementia, stroke, spinal cord injury), inflammatory bowel disease, peripheral neuropathy 1

Stepwise Treatment Algorithm

Step 1: Conservative Management (MANDATORY FIRST-LINE)

Critical pitfall: Many patients labeled "refractory" have never received optimal conservative therapy. 1, 2 You must implement ALL appropriate measures below:

Dietary and Lifestyle Modifications

• Meticulous characterization of bowel habits and circumstances surrounding incontinence episodes (relationship to meals, activity) 1
• Trial elimination of poorly absorbed sugars (sorbitol, fructose) and caffeine in patients with diarrhea—benefits approximately 25% of patients 1, 2
• Fiber supplementation to improve stool consistency and reduce diarrhea-associated incontinence 1, 2
• Adequate fluid intake 1

Pharmacologic Management for Diarrhea

• Loperamide 2 mg: Start with 1 tablet 30 minutes before breakfast, titrate up to 16 mg daily as needed 1, 2, 3
• Loperamide works by slowing intestinal motility, increasing intestinal transit time, and increasing anal sphincter tone to reduce urgency and incontinence 3
• Bile-salt malabsorption is common in idiopathic diarrhea: Consider cholestyramine or colesevelam 1
• Alternative options: Anticholinergic agents and clonidine 1

Behavioral Interventions

• Scheduled toileting and bowel training programs to establish regular habits 1, 2
• Pelvic floor exercises to strengthen musculature (effective even in elderly patients) 1, 2

Step 2: Biofeedback Therapy

Pelvic floor retraining with biofeedback therapy using electronic and mechanical devices to improve pelvic floor strength, sensation, contraction, and rectal tolerance of distention. 1 This has resulted in 90% reduction in incontinence episodes in over 60% of patients. 4

Step 3: Advanced Diagnostic Testing (If Conservative Measures Fail)

• Anorectal manometry to identify anal weakness, altered rectal sensation, or impaired rectal balloon expulsion 2
• Anal imaging (endoanal ultrasound) to identify sphincter defects, atrophy, and patulous anal canal 2
• Pudendal nerve terminal motor latencies (PNTML) are the most important predictor of surgical outcome 4

Step 4: Minimally Invasive Interventions

Sacral nerve stimulation is the preferred surgical option when conservative therapy fails, with 71% of patients achieving ≥50% reduction in incontinence episodes at 12 months. 1, 2

• Perianal bulking agents may be considered, with 52% showing ≥50% improvement at 6 months 1, 2
• Barrier devices can be considered before more invasive procedures 1

Step 5: Surgical Options (For Refractory Cases)

• Sphincteroplasty (overlapping anterior sphincteroplasty) has good to excellent results in 70-90% of patients, but only in the absence of pudendal neuropathy 4
• Magnetic anal sphincter device may be considered for severe refractory FI, though 40% experience moderate to severe complications 1
• Colostomy remains the final option 1

Special Considerations for Elderly Patients

• Ensure toilet access with decreased mobility as a critical prevention measure 2
• Optimize toileting: Educate patients to attempt defecation twice daily, 30 minutes after meals, straining no more than 5 minutes 2
• Use polyethylene glycol 17 g/day for elderly patients requiring laxatives (good safety profile) 2
• Avoid liquid paraffin in bed-bound patients or those with swallowing disorders due to aspiration pneumonia risk 2
• Use isotonic saline enemas rather than sodium phosphate enemas to avoid adverse effects 2
• Monitor for dehydration and electrolyte imbalances when using laxatives in patients on diuretics or cardiac glycosides 2
• Do not use bulk laxatives in non-ambulatory patients with low fluid intake (risks mechanical obstruction) 2

Clinical Success Metrics

A 50% reduction in the number of incontinence episodes or days with FI is considered clinically significant improvement. 1 Severity assessment tools include Wexner Score, Modified Manchester Health Questionnaire, Fecal Incontinence Severity Score, and Fecal Incontinence Severity Index. 1