Traveler's diarrhea (TD) is the most common illness affecting travelers.An estimated 10 million people—20% to 50% of international travelers—develop it annually. TD is defined as three or more unformed stools in 24 hours passed by a traveler, commonly accompanied by abdominal cramps, nausea, and bloating.Its diagnosis does not imply a specific organism, but enterotoxigenic Escherichia coli is the most commonly isolated pathogen.Most cases are self-limited; treatment is not routinely prescribed nor the pathogen identified unless symptoms become severe or persistent.
The onset of TD usually occurs within the first week of travel, but may occur at any time while traveling, and even after returning home. When it appears depends in part on the specific infectious agent. The incubation period for giardiasis averages about 14 days and that of cryptosporidiosis about seven days. Certain other bacterial and viral agents have shorter incubation periods, although hepatitis may take weeks to manifest itself. Most TD cases begin abruptly.
Typically, a traveler experiences four to five loose or watery bowel movements each day. Other commonly associated symptoms are diarrhea, abdominal cramping, bloating, low fever, urgency, disability to hold the feces and malaise, and appetite is usually low or nonexistent.
Blood or mucus in the diarrhea, abdominal pain, or high fever heralds a more serious cause, such as cholera, characterized by a rapid onset of symptoms including weakness, malaise, and torrents of watery diarrhea with flecks of mucus (described as "rice water" stools). Dehydration is a serious consequence of cholera; death may (rarely) occur as quickly as 24 hours after onset.
Most cases of TD are mild and resolve in a few days without treatment with antibiotics or antimotility drugs. Severe or protracted cases, however, may result in significant fluid loss and dangerous electrolytic imbalance. Adequate fluid intake (oral rehydration therapy) is essential to replace lost fluids and electrolytes. Clear, disinfected water or other liquids are routinely recommended for adults.Water that is purified is best, along with oral rehydration salts to replenish lost electrolytes. Carbonated water (soda), which has been left out so that the carbonation fizz is gone, is useful if nothing else is available. In severe or protracted cases, the oversight of a medical professional is advised.