• Ciprofloxacin, 500 mg twice daily for 5 days (or one of the other fluoroquinolones)
• Bismuth subsalicyate (Pepto-Bismol), 2 tablets with every meal and at bedtime for 5 days
• Bactrim DS, one tablet twice daily for 3 days (Note: Many organisms are now resistant to Bactrim.)

Reference: Sleisenger MH, Fordtran JS (eds): Gastrointestinal Disease: Pathophysiology, Diagnosis, and Management, 7th ed. Philadelphia, W.B. Saunders, 2003

• Enterotoxigenic E. coli
• Shigella sp.
• Campylobacter jejuni
• Plesiomonas sp.
• Rotavirus
• Cryptosporidium sp.
• Enteroaggregative E. coli
• Salmonella sp.
• Aeromonas sp.
• Norwalk virus
• Giardia sp.
• Cyclospora sp.

Reference: Lichetenstein GR, Wu GD (eds): The Requisites in Gastroenterology: Vol 2: Small and Large Intestines. St. Louis, Mosby, 2003

Travelers should carefully select, handle and prepare food and dairy products. Everything should be washed thoroughly and freshly cooked. Commercially bottled water, carbonated beverages, and beer are safe-but ice is not!

Reference:  Lichetenstein GR, Wu GD (eds): The Requisites in Gastroenterology: Vol 2: Small and Large Intestines. St. Louis, Mosby, 2003

Traveler’s diarrhea is a common term given to the onset of diarrhea in patients who have traveled to other countries, usually in the third world, where the enteric flora are different. Eighty percent of cases are caused by bacteria that can be transmitted via a fecal-oral route. Viruses account for 10% of cases, and parasites cause 2-3%. In the remainder of cases the cause is unknown.

Reference:  Sleisenger MH, Fordtran JS (eds): Gastrointestinal Disease: Pathophysiology, Diagnosis, and Management, 7th ed. Philadelphia, W.B. Saunders, 2003

The term dysentery refers to a diarrheal stool that contains inflammatory exudate (pus) and blood. Bacillary dysentery refers to infectious diarrhea caused by invasive pathogens, most commonly, Shigella, Salmonella, Campylobacter, and enteroinvasive or enterohemorrhagic Escherichia coli.

Reference:  Sleisenger MH, Fordtran JS (eds): Gastrointestinal Disease: Pathophysiology, Diagnosis, and Management, 7th ed. Philadelphia, W.B. Saunders, 2003

1. The stool osmolar gap is < 50 mOsm/kg in secretory diarrhea but is > 50 mOsm/kg in osmotic diarrhea.
2. Secretory diarrhea is typically unrelated to ingested foods or solutes and persists during a 24-72-hour fast, whereas osmotic diarreha stops when ingestion of the offending solute ends.
3. Patients with a pure secretory diarrhea do not have WBCs, RBCs, or fat in their stool.

Reference: Sleisenger MH, Fordtran JS (eds): Gastrointestinal Disease: Pathophysiology, Diagnosis, and Management, 7th ed. Philadelphia, W.B. Saunders, 2003

Osmotic diarrhea is caused by ingestion of excessive amounts of a poorly absorbable but osmotically active solute. Commonly implicated substances include mannitol or sorbitol (seen in patients chewing large quantities of sugar-free gum), magnesium sulfate (Epsom salt), and some magnesium-containing antacids. Carbohydrate malabsorption also may cause osmotic diarrhea through the action of unabsorbed sugars (lactulose). Clinically, osmotic diarrhea stops when the patient fasts (or stops ingesting the poorly absorbable solute).

Reference:  Sleisenger MH, Fordtran JS (eds): Gastrointestinal Disease: Pathophysiology, Diagnosis, and Management, 7th ed. Philadelphia, W.B. Saunders, 2003