What are the diagnosis and treatment options for a patient presenting with fecal incontinence?

Fecal Incontinence: Diagnosis and Treatment

Initial Diagnostic Evaluation

Begin with a detailed characterization of incontinence patterns, including type (urge vs passive), frequency, stool consistency, relationship to meals and activity, and impact on quality of life, as this guides all subsequent management decisions. 1, 2

Key History Elements

• Determine premorbid bowel patterns and circumstances of incontinence episodes, including timing relative to meals, physical activity, and any prior treatments attempted 1
• Evaluate for diarrhea as the primary driver, as bowel disturbances and rectal urgency are significant independent risk factors for fecal incontinence 1, 2
• Review all medications systematically, particularly opioids, anticholinergics, and cyclizine, which worsen bowel dysfunction 1
• Assess mobility status, as needing assistance getting to the toilet is a strong independent risk factor 1
• Obtain dietary history focusing on poorly absorbed sugars, lactose, and caffeine, as these commonly trigger diarrhea-associated incontinence 1

Physical Examination

• Perform a careful digital rectal examination assessing pelvic floor motion during simulated evacuation, including evaluation of resting anal tone, squeeze effort, puborectalis contraction, and ability to expel the examining finger 3
• Examine for rectocele or consider gynecologic consultation for structural abnormalities 3
• Note that a normal digital rectal examination does not exclude defecatory disorders 3

Laboratory and Structural Evaluation

• Obtain complete blood count only, unless other symptoms warrant additional testing 3
• Metabolic tests (thyroid-stimulating hormone, glucose, calcium) are not recommended for chronic constipation in the absence of other symptoms 3
• Colonoscopy should not be performed unless alarm features are present (blood in stools, anemia, weight loss) or age-appropriate screening has not been completed 3

Stepwise Treatment Algorithm

First-Line Conservative Management

Start with conservative measures including dietary modification, fiber supplementation, scheduled toileting, and loperamide for diarrhea-associated incontinence before progressing to more invasive interventions. 1

Dietary and Lifestyle Modifications

• Conduct elimination trials of poorly absorbed sugars and caffeine identified in dietary history 1
• Add fiber supplementation to improve stool consistency and reduce diarrhea-associated incontinence 1

Pharmacologic Management for Diarrhea-Associated Incontinence

• Start loperamide 2 mg taken 30 minutes before breakfast, titrating up to 16 mg daily as needed 1
• This addresses the most common modifiable risk factor for incontinence 2

Behavioral Interventions

• Implement scheduled toileting every 2 hours while awake and every 4 hours at night to establish a bowel routine 1
• Establish bowel training program with consistent timing after meals to utilize the gastrocolic reflex 1

Second-Line: Diagnostic Testing (When Conservative Measures Fail)

Perform anorectal manometry to identify anal weakness, altered rectal sensation, and impaired rectal balloon expulsion, as this determines candidacy for biofeedback versus surgical interventions. 3, 1

• Anorectal manometry is the critical diagnostic tool that identifies pathophysiological abnormalities including dyssynergic defecation, anal sphincter weakness, and rectal sensory dysfunction 3
• Add endoanal ultrasound or MRI to visualize internal and external sphincter defects when considering surgery or device placement 1
• Fluoroscopic cystocolpoproctography can reveal clinically occult sigmoidoceles, enteroceles, and rectoanal intussusceptions 3

Third-Line: Biofeedback Therapy

Biofeedback is the next step after basic conservative measures fail, using electronic and mechanical devices to improve pelvic floor strength, sensation, and rectal tolerance. 1

• Biofeedback can improve symptoms in more than 70% of cases of defecatory disorders 1
• This is particularly effective for patients with dyssynergic defecation identified on anorectal manometry 3
• Biofeedback is safe, well-tolerated, and should be attempted before surgical options 4

Fourth-Line: Minimally Invasive Interventions

Perianal Bulking Agents

• Dextranomer microspheres in non-animal stabilized hyaluronic acid (NASHA Dx) is FDA-approved, with 52% of patients achieving ≥50% improvement in incontinence episodes at 6 months 1
• Consider this before more invasive surgical options 3

Sacral Nerve Stimulation

• Sacral nerve stimulation should be considered for patients who fail conservative therapy, biofeedback, and perianal bulking 1
• Reserved for medically-refractory severe fecal incontinence 3
• Do not use percutaneous tibial nerve stimulation, as evidence does not support its use 3

Barrier Devices

• Offer barrier devices to patients who have failed conservative or surgical therapy, or those who failed conservative therapy but do not want or are not eligible for more invasive interventions 3

Fifth-Line: Surgical Interventions

Sphincteroplasty

• Consider anal sphincter repair in postpartum women with fecal incontinence and patients with recent sphincter injuries 3, 1
• In patients presenting later with symptoms unresponsive to conservative and biofeedback therapy with evidence of sphincter damage, sphincteroplasty may be considered when perianal bulking and sacral nerve stimulation are unavailable or unsuccessful 3

Correction of Anatomic Defects

• Major anatomic defects (rectovaginal fistula, full thickness rectal prolapse, fistula in ano, cloacalike deformity) should be rectified surgically 3, 1

Advanced Surgical Options

• Magnetic anal sphincter device may be considered for patients with medically refractory severe fecal incontinence who have failed or are not candidates for other interventions, though 40% experience moderate or severe complications 3
• Artificial anal sphincter and dynamic graciloplasty may be considered for severe refractory cases who have failed all other treatments except colostomy 3

Colostomy

• Colostomy should be considered in patients with severe fecal incontinence who have failed conservative treatment and are not candidates for or have failed barrier devices, minimally invasive surgical interventions, and sphincteroplasty 3, 1

Critical Clinical Caveats

• Many patients considered "refractory" have not received optimal conservative therapy, including meticulous characterization of bowel habits, dietary elimination trials, and appropriate titration of antidiarrheal medications 1
• A 50% reduction in incontinence episodes is considered clinically significant improvement in clinical trials 3, 1
• Fecal incontinence has devastating impact on quality of life, causing loss of confidence, self-respect, and social isolation, yet many patients do not volunteer this symptom due to embarrassment 3, 1, 2
• Pudendal nerve terminal motor latencies are the most important predictor of functional outcome for surgical interventions—sphincteroplasty is excellent in the absence of pudendal neuropathy, but alternative procedures should be considered if neuropathy exists 5
• Do not routinely perform STARR and related procedures for correction of structural abnormalities in patients with defecatory disorders 3