Subtypes

Definition: ≥ 3 unformed stools with at least one additional enteric symptom occurring after recent travel

Epidemiology

• The highest rates occur after travel to Africa and South, Central, and West Asia.

• Approximately 25% of all travelers develop traveler's diarrhea.

Etiology

• Enterotoxigenic E. coli (ETEC) is the most common cause of traveler's diarrhea globally.

• Campylobacter jejuni is the most common cause in Southeast Asia.

• Other pathogens

  • Bacterial: Shigella spp., Salmonella spp., other E. coli strains (e.g., EAEC)

  • Viral: norovirus, rotavirus, astrovirus

  • Protozoal: Giardia duodenalis, E. histolytica

Clinical features: exudative-inflammatory or secretory diarrhea, abdominal cramping, abdominal pain

Antibiotics: Reserve for moderate to severe illness. [24][31][35]

• For most destinations: ciprofloxacin OR rifaximin

• For travelers to South or Southeast Asia: azithromycin

Supportive care [24]

• Treatment for dehydration (e.g., oral rehydration solution)

• Bismuth subsalicylate for patients with mild to moderate illness

• Loperamide for patients receiving antibiotic therapy (can reduce the duration of illness)

Definition: self-induced diarrhea, usually due to laxative abuse (often occurs in individuals with factitious disorders), or dilution of stools with solutions

Epidemiology

• Most prevalent in women

• Patients are usually health care professionals.

• History of multiple hospital admissions

Clinical features: chronic diarrhea without an identifiable cause

Diagnostics

• Laboratory tests: metabolic acidosis , metabolic alkalosis , hypokalemia, hypermagnesemia

• Stool osmolarity

  • < 290 mOsm/L: indicates dilution of the stool with a hypotonic solution

  • > 600 mOsm/L: indicates dilution of the stool with a hypertonic solution

• Laxative screen [17]

• Colonoscopy: may show melanosis coli in cases of anthraquinone abuse

Treatment

• Correction of electrolyte disturbances and dehydration

• Referral for psychotherapy

Types of laxative

• Bulking agent: e.g., flaxseed

• Osmotic laxatives: e.g., lactulose, macrogols (polyethylene glycol), magnesium sulfate, sodium sulfate

• Diphenolic laxatives: bisacodyl, sodium picosulfate

• Anthraquinones: e.g., senna, aloe vera, rhubarb

Clinical features

• Osmotic diarrhea, meteorism

• Dehydration

• Hypokalemia

• Melanosis coli: benign hyperpigmentation of the colonic mucosa caused by anthraquinone abuse [38]

  • Colonoscopy: patches of dark brown pigmentation interspersed with pale mucosa

  • Biopsy: lipofuscin-laden macrophages demonstrated on periodic acid-Schiff staining

Definition: secretory diarrhea with or without steatorrhea due to increased colonic secretion and motility secondary to an increased concentration of bile acids within the colon

Epidemiology: approx. 1% global prevalence [39]

Etiology

• Ileal dysfunction or decreased bile acid reabsorption in the ileum (e.g., due to ileal resection, Crohn disease)

• Postcholecystectomy

• Hepatic overproduction of bile acids

• Biliary-enteric fistula

Clinical features

• Bowel frequency and urgency

• Fecal incontinence

• Abdominal cramping, abdominal pain

• Nocturnal fecal urgency

• Bloating, flatulence

Management [40]

• First-line: bile-acid sequestrants (e.g., cholestyramine, colestipol)

• Dietary intervention: low-fat diet