Traveler's Diarrhea (Infectious Gastroenteritis; Turista)

Traveler's diarrhea is characterized by the passage of four or five loose, watery stools a day, usually for two to four days. Studies show that 20 to 50 percent of travelers develop diarrhea, but the incidence varies greatly according to destination. For Americans, the developing countries of Latin America, Africa, the Middle East, and Asia pose the greatest risk. But travelers who go any place where their intestinal tracts encounter unfamiliar micro-organisms can acquire diarrhea. For example, Mexicans often develop the problem when visiting the United States.

Numerous bacteria, viruses, and protozoa can cause travelers diarrhea, but 40 percent of cases are caused by strains of E. coli. When these bacteria enter the small intestine, they produce a toxin that induces the intestinal wall to draw in large amounts of water and salt. Although the large intestine can absorb several quarts of liquid a day, it is quickly overwhelmed by the excessive water flowing in from the small intestine, resulting in diarrhea. Until the bacteria are washed out (about 48 hours), the person is likely to suffer abdominal cramps and may also experience nausea and vomiting.

Other organisms that commonly cause traveler's diarrhea include Shigella, Salmonella, various viruses, and protozoa such as Giardia lamblia. Cryptosporidium, an intestinal parasite that has been found in water here and abroad, is an increasingly common cause of a more serious form of diarrhea that may last 10 or more days.

Diagnostic Studies and Procedures

Traveler's diarrhea can usually be diagnosed on the basis of its symptoms. Blood tests and a stool culture may be ordered if the diarrhea persists for more than three or four days, or if it is accompanied by a high fever, blood in the stools, and other severe symptoms.

Medical Treatments

Most traveler's diarrhea is self-limiting and requires no care other than fluid replacement to prevent dehydration (see Self-Treatment). Most doctors advise against taking anti-diarrheal medications, because they may slow recovery. However, if diarrhea is interfering with travel, some may prescribe an antibiotic such as trimethoprim with sulphamethoxazole (Bactrim or Septra) or ciprofloxacin (Cipro). Metronidazole (Flagyl) is used for giardiasis or other parasitic infections.

For situations in which it is difficult to get to a bathroom, loperamide (Imodium) or codeine, drugs that slow intestinal motility, may be recommended. Some doctors prescribe a combination of Bactrim and Imodium for two or three days for travelers who want relief from their symptoms.

Alternative Therapies

Herbal Medicine. Chamomile or ginger tea can help settle the stomach. Teas made of barberry, cayenne pepper, or summer savory are said to alleviate diarrhea. Caution is called for, however, because some of these may further irritate the intestinal tract.

Homeopathy. Practitioners recommend arsenicum, veratrum album, and belladonna to treat diarrhea.

Naturopathy. Naturopaths advocate switching to a liquid diet during the acute phase and reintroducing foods slowly. They also suggest drinking 3 cups of boiled rice water a day. This is made by boiling a cup of brown rice in 6 cups of water for 45 minutes, then straining it.

Self-Treatment

Prevention is the best approach. When traveling, eat at clean, long established restaurants. Select well-cooked foods; avoid raw vegetables, unpeeled fruits, and unpasteurized milk and milk products. Use only bottled or boiled water for drinking and brushing your teeth. Don't use ice cubes unless you know they were made with sterile water. Wash your hands frequently and always before eating or handling foods.

People who follow these precautions can still develop diarrhea, so it's wise to take preventive medicine with you. One study found that travelers to Mexico who took two bismuth tablets four times a day cut their risk of diarrhea from 63 to 21 percent. Alternatively, low-dose prophylactic antibiotics may be taken; ask your doctor about a prescription.

If diarrhea does develop, you will probably need a couple of days to recover. Bismuth tablets or non-prescription diarrhea products are generally safe, but may prolong the diarrhea.

Replacing lost fluids is essential, especially in young children and the elderly. It's wise to carry packets of a re-hydration replacement product that you can reconstitute with sterile water.