To avoid traveler's diarrhea, don't drink tap water while traveling or use it to brush your teeth, unless you know the water is safe. Also avoid ice that was made from potentially unsafe tap water. And don't consume unpasteurized milk or dairy products or raw fruits and vegetables unless they can be peeled to remove any bacteria that might be on the outside, suggests the National Digestive Diseases Information Clearinghouse. Travelers should also avoid raw or rare fish and meat and avoid eating shellfish or meat that isn't hot when served. Bottled water is safe as long as you are the one to open it, as are carbonated soft drinks, coffee, and tea. Depending on the location you're traveling to and how long you'll be there, your doctor might prescribe antibiotics before you go if you're really worried about traveler's diarrhea, according to the NDDIC. But the CDC does not recommend this practice because routinely using antibiotics when traveling puts people at risk for adverse reactions and for infections that are resistant to the medication.
Use of acid-suppressing medications, such as those used to treat heartburn or reflux, can increase infection risk as well. These medications neutralize stomach acids, which are "nature's way of killing most ingested bugs," Wren says. "So counteracting this natural defense may lead to higher numbers of bugs such as Campylobacter surviving and getting into your intestines, where they cause infection." The solution? "Only take antacids if you require them," he says.