Use common sense, simple tips to avoid traveler's diarrhea

DEAR DOCTOR K: I'm about to travel to a developing country. How can I avoid traveler's diarrhea?

DEAR READER: Traveler's diarrhea comes from eating food or drinking water contaminated by certain bacteria, viruses and parasites - particularly the bacteria called enterotoxigenic E. coli. About half of the people traveling to a developing country come down with traveler's diarrhea. Fortunately, it is usually not severe. Still, it can spoil a good vacation.

Keep the following rules in mind, even in expensive resorts and hotels:

- Purify water by boiling it for at least three minutes or using a water purifier.

- Carbonated beverages and bottled water are usually safe. Drink from the bottle with a straw, rather than out of a glass. The glass may have been washed with contaminated water.

- Don't use ice, which could be contaminated.

- Brush your teeth with boiled, bottled or purified water.

- Hot coffee and tea usually are safe.

- Don't eat fruits and vegetables unless you can peel them yourself.

- Avoid unpasteurized dairy products and undercooked meat and fish.

- If clean water isn't available, disinfect your hands with alcohol wipes before eating.

If you're in a developing country and a guide tells you that the vegetables and unpeeled fruits at a particular restaurant are fine, thank him for the advice but don't take it. I did once, and instead of spending the next day immersed in the dramatic pageant of life on the Serengeti, I spent the day in a bathroom - and a rather unpleasant one, at that.

Two tablets of bismuth subsalicylate (Pepto-Bismol) four times a day can decrease your risk of diarrhea. But don't do this for more than three weeks.

Also, don't take antibiotics to prevent diarrhea unless your doctor tells you to. They can prevent diarrhea, but they also can lead to side effects such as allergic reactions, severe skin rashes if you're in the sun a lot (which usually is the case) and vaginal yeast infections. Ironically, you can also develop a serious type of diarrheal illness called C. difficile colitis from taking antibiotics to prevent traveler's diarrhea.

Dehydration is the biggest danger of traveler's diarrhea. Here are some recommendations if you do get sick:

- If you have mild diarrhea, drink broth and diluted fruit juice or sport drinks.

- If you have severe diarrhea, drink an oral rehydration solution. This is available in pharmacies in most countries. You can also make your own solution by adding a half-teaspoon of salt, a half-teaspoon of baking soda and 4 tablespoons of sugar to 1 liter of clean water.

- Ask your doctor about bringing antibiotics on your trip. Take antibiotics if you develop moderate or severe symptoms.

- Loperamide (Imodium) or diphenoxylate (Lomotil) can help decrease the frequency of bowel movements.

Get medical attention if your diarrhea lasts longer than five days, or if you develop a high fever, bloody stool or abdominal pain.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.