Description

• Laxative abuse may be intentional or unintentional and manifests commonly as watery diarrhea caused by self-medication or as apparent diarrhea caused by adding various fluids to stool:
  • Common cause of chronic diarrhea are diverse, reflecting demographics of individual or population studied.
• System(s) affected: Gastrointestinal; Nervous; Psychiatric
• Synonym(s): Factitious diarrhea; Cathartic colon; Münchausen syndrome (self or by-proxy)—most dramatic form

Epidemiology

• Predominant age: 18–40 years with bulimia or anorexia nervosa; 40–60 years without eating disorders
• Common in the elderly as a result of treatment for constipation, either by MD or self-directed (unintentional)
• Predominant sex (intentional abuse): Female (90%) > Male
• Children may be given excess laxation by caregivers (especially mothers), an example of Münchausen syndrome by proxy.
• May coexist with diverse manifestations of factitious illness (endocrine, skin, neurologic)

• As many as 15% undergoing evaluation for chronic diarrhea
• Unexplained chronic diarrhea after routine investigations: 3.5–7%
• Patients with binging/purging anorexia and bulimia nervosa: As high as 70%
• Referrals to tertiary-care centers for evaluation of chronic diarrhea: As high as 15%
• Chronic use of constipating medications such as opioids

Geriatric Considerations
Elderly in nursing homes at increased risk for laxative overuse (usually inadvertent)

Risk Factors

In patients with eating disorders (2):

• Longer duration of illness
• Comorbid psychiatric diagnoses (e.g., major depression, obsessive–compulsive disorder, posttraumatic stress disorder, anxiety, borderline personality disorder)
• Early age of appearance of eating disorder symptoms

General Prevention

• Educate patients about proper nutrition, normal bowel function, potential adverse effects of excessive laxation, and use of additional medications (e.g., magnesium-containing antacids) that can cause diarrhea.
• Ask patients specifically about laxative use. Inadvertent overuse is common.

Etiology

• Chronic ingestion of any laxative agent:
  • Osmotic diarrhea: Magnesium sulfate, nonabsorbable sugars, sodium phosphate
  • Secretory diarrhea: Dihydroxy bile salts, castor oil, docusate sodium
• Psychologic factors:
  • Bulimia or anorexia nervosa
  • Secondary gain of attention: Disability claims or need for concern, caring from others
  • Hysterical behavior
  • Inappropriate perceptions of “normal” bowel habits
  • Chronic constipation, especially in the elderly

Commonly Associated Conditions

• Anorexia nervosa, bulimia nervosa
• Use of constipating medications (opioids, iron supplements)
• Any chronic disorder associated with constipation
• Depression and anxiety
• Borderline personality
• Self-injurious behaviors/suicidal ideation
• Impulsive behavior
• Münchausen syndrome/Münchausen syndrome by proxy; may have associated factitious symptoms involving diverse organ systems