Travelers Diarrhea - Diarrhea: Digestive Disorders

Content provided by the Faculty of the Harvard Medical School

Traveler's diarrhea

Some of the worst cases of diarrhea are those experienced by people who travel, particularly to developing countries. Bacteria and the toxins that cause diarrhea are present in areas with contaminated water supplies, poor sewage systems, or inadequate food handling or preparation techniques.

Traveler's diarrhea (TD) causes cramps, bloating, nausea, a general sick feeling, and fever. Sometimes, the diarrhea may be violent and frequent — an average of five episodes of loose, watery stools a day. It may last from three or four days to a week. Studies show that 50% of tourists to developing countries develop diarrhea. High-risk destinations include Latin America, Africa, and the Middle East.

When traveling, take extra precautions to avoid bacteria and viruses.

For travelers, raw foods of all types are the most risky. Where one eats is also important: Street vendors are the most dangerous. And water, of course, is critical. Tap water should be avoided at all costs. Even using it to brush your teeth is dangerous. A single drop of contaminated water on a piece of lettuce, for example, can carry millions of TD-causing bacteria.

Fortunately, there are ways to help prevent TD. First, adhere to the old adage, "If you can't cook it, boil it, or peel it, forget it." When avoiding the local tap water, also avoid ice cubes. And use bottled water for everything. If bottled water isn't available, you can carry a portable water filter, or you can treat tap water by boiling it for 10 minutes or by adding one iodine tablet to a quart of water 30 minutes before drinking.

While there are no vaccines available for TD, travelers can help protect themselves by taking two tablets of Pepto-Bismol four times a day before and during international travel. This can cut the risk by 60%, according to studies. The medicine may also be started at the first sign of diarrhea. Some people take diphenoxylate with atropine (Lomotil) or loperamide (Imodium), which also appear to be effective.

In 2004, the FDA approved the antibiotic rifaximin (Xifaxan) for the treatment of traveler's diarrhea. The drug has been available in many other countries for more than 18 years. Whereas most antibiotics spread throughout the body, rifaximin remains within the GI system, so side effects are less likely. Rifaximin taken at the onset of symptoms will probably decrease the intensity and duration of symptoms. Since unnecessary antibiotic use is discouraged (to prevent resistant strains from developing), rather than automatically taking rifaximin when your trip begins, you may want to carry it with you to start in case you do develop diarrhea.

A vaccine for rotavirus, which causes a syndrome of diarrhea and vomiting that kills hundreds of infants every year in the United States and millions worldwide, became available in 1998; however, it was pulled from the market in 1999 because some infants developed bowel blockages. A newer version of the vaccine that does not cause this problem is being developed and may be available in the near future. Other vaccines to prevent diarrhea, including an oral vaccine that kills E. coli, are also in development.

Last updated:	August 21, 2007