Definition: Acute, self-limited diarrhea (3–5 loose stools/day) in a traveler, typically caused by enterotoxigenic E. coli (ETEC), Salmonella, Shigella, or Campylobacter.

• Epidemiology: Highest risk in South Asia, Latin America, and Africa; 20–50% of travelers develop it.
• Diagnosis:
  • Clinical: Sudden onset of diarrhea, often with nausea, cramps, and low-grade fever.
  • Stool testing: Not routinely needed; reserved for severe cases (fever, blood, persistent symptoms).
• Treatment:
  • Mild cases: Oral rehydration, loperamide (if no fever/blood), and self-limiting.
  • Moderate/severe cases:
    • Antibiotics: Azithromycin (500 mg once) or ciprofloxacin (500 mg twice daily for 3 days) if no improvement in 24–48 hours.
    • Rationale: ETEC is often resistant to quinolones in South Asia; azithromycin is first-line in these regions.
  • Prophylaxis: Bismuth subsalicylate (2 tablets qid) or rifaximin (200 mg daily) for high-risk travelers.
• Complications: Post-infectious IBS (20–30% of cases), hemolytic uremic syndrome (E. coli O157:H7), or chronic diarrhea (rare).
• Guidelines: IDSA (2006) recommends empiric treatment with antibiotics for moderate/severe cases.

Key Points:

• Empiric antibiotics for moderate/severe cases; regional resistance patterns matter.
• Prophylaxis for high-risk travelers (e.g., immunocompromised, short trips).
• Post-infectious IBS is a significant long-term risk.