DAVID GREENE, HOST:
And speaking of unhealthy menus, maybe you've come across some while traveling, maybe to that place where people warned you don't eat that food from those outdoor vendors. You didn't listen though because it just looked so good, but then it didn't agree with you. Well, doctors will tell you it isn't actually the food but the bacteria that's on it. And what you think might protect you probably won't. Here's NPR's Michaeleen Doucleff.
MICHAELEEN DOUCLEFF, BYLINE: Travel doctor David Shlim has spent 30 years trying to figure out what it is that makes tourists sick. He says that 90 percent of the time, the culprit are bacteria - not just different ones that your stomach isn't used to.
DAVID SHLIM: No, it's not. It really - a lot of studies have shown that when people have diarrhea, they're sick with a particular kind of bacteria that is known to cause diarrhea.
DOUCLEFF: And that would make you sick anywhere, even here in the U.S. So what can you do about it? Just wash your hands before you eat? Wrong.
SHLIM: The fact is, is that it usually takes a certain high quantity of bacteria, sometimes in the millions, to overcome your stomach acid. And so just the random bacteria that you get on your hands, I think, is unlikely to make you sick.
DOUCLEFF: Instead, Shlim says the major source of almost all travelers' diarrhea around the world is contaminated food and water at restaurants.
SHLIM: Most people can avoid drinking untreated water either by getting boiled water, or drinking bottled water or treating it themselves.
DOUCLEFF: But avoiding contaminated food is trickier. Shlim says many travelers swear by the old saying - boil it, peel it or forget it. But scientific studies don't back it up. Eating raw vegetables and un-peeled fruits haven't been linked to getting sick. Shlim says there is one thing though that that seems to work.
SHLIM: High temperature. So food that is cooked hot - too hot for you to initially, you know, bite into right when it comes to your plate - you know, that makes safe foods. It's just hard to put together a meal of everything that is super hot at the same time.
DOUCLEFF: So in the end whether you get sick or not often boils down to bad luck. But if you do find yourself making several mad dashes to the restroom, Shlim says take a quick dose of antibiotics. Chances are, you'll feel much better the next day. Michaeleen Doucleff, NPR News. Transcript provided by NPR, Copyright NPR.