Fecal incontinence

Fecal incontinence is a condition characterized by the involuntary loss of solid or liquid feces. Causes and presentations are variable. Fecal incontinence remains a grossly underreported condition in the US and affects approximately 8% of adults older than 65 years of age. Prevalence is similar in women and men. Diagnosis involves a detailed medical history, physical examination, and diagnostic testing such as the evaluation of the neuromuscular function of the anorectum (anorectal manometry). Treatment is determined based on the etiology, and usually involves supportive measures such as dietary changes, pelvic floor physiotherapy, and medical therapy aimed at reducing stool frequency and improving stool consistency. Complications include perianal dermatitis and psychological distress.

• Fecal incontinence (FI): the involuntary loss of feces
• Fecal urge incontinence: lack of ability to retain stool despite efforts to do so
• Passive fecal incontinence: the involuntary loss of stool without awareness of the need to defecate preceding the event

• Prevalence: 8.3% of adult individuals in the US
• Sex: ♀=♂
• Risk factors ^[1]
  • > 65 years of age
  • Functional dependency: dementia, physical disability (e.g., spinal cord injury, pudendal nerve injury)

References: ^[2][3]

Epidemiological data refers to the US, unless otherwise specified.

• Bowel disorders
  • Chronic diarrhea
  • Constipation
  • Inflammatory bowel disease
  • Irritable bowel syndrome
• Overflow disorders
  • Urinary incontinence
  • Fecal retention and/or impaction
• Pregnancy: related to childbirth (e.g., instrumental delivery, prolonged second stage of labor)
• Surgery: e.g., fistulotomy
• Neuropathic disorders
  • Diabetes mellitus
  • Multiple sclerosis
  • Spinal cord injury (e.g., cauda equina syndrome)
• Rectal and anal disorders
  • Rectal prolapse
  • Rectocele
  • Hemorrhoids
  • Anal fistulas
• Other: hormone replacement therapy, pelvic radiation

References: ^[4]

• Chronic or recurring fecal leakage
• May be associated with flatus, abdominal discomfort, and/or bloating

• Physical examination
  • Digital rectal exam: identify rectal masses, assess anal sphincter tone
  • Perianal area exam: inspection, perianal pinprick sensation, anal wink reflex
• Anorectal manometry: first diagnostic test
• Balloon expulsion test: a test performed to diagnose defecatory disorders by assessing an individual's ability to evacuate a simulated stool.
  • A latex balloon attached to a catheter is inserted into the patient's rectum and filled with 50 mL of fluid. Afterward, the patient is given privacy and asked to expel the balloon into a toilet.
  • Positive test: inability to expel the balloon within 60 seconds is suggestive of a defecatory disorder
  • Performed when there is suspicion of underlying dyssynergic defecation
• Other studies
  • Pelvic floor and anal MRI or anorectal ultrasound: detect structural abnormalities
  • Colonoscopy: in individuals with risk factors for colorectal cancer
  • Barium defecography: performed in individuals with refractory fecal incontinence
  • Anal sphincter electromyography
    • A procedure involving the insertion of a small sponge electrode into the anal canal to record sphincter muscle electrical activity
    • Performed when there is suspicion of underlying nerve injury

References: ^[4]

• Supportive measures
  • Dietary changes
  • Keeping a food diary
  • Bowel control exercises
• Medical therapy
  • Depending on the underlying cause
  • Aimed at reducing stool frequency and improving consistency: fiber supplements, antidiarrheal medications (e.g., loperamide)
• Biofeedback therapy: cases of external anal sphincter weakness or nerve injury
• Surgical therapy: reserved for patients with refractory fecal incontinence or significant structural abnormalities (e.g., rectal prolapse, rectocele)

References: ^[4]

• Psychological distress
• Perianal dermatitis

We list the most important complications. The selection is not exhaustive.