Here's some tips on playing it safe to stay healthy on vacation. — Photo by Steven Errico/Getty Images

See Also: Avoid these 4 health travel risks.

There's a basic rule of thumb when it comes to eating food in developing countries: boil it, peel it, cook it, or forget it. But even the most cautious travelers tend to overlook the obvious. They think they're playing it safe by ordering soda...with ice. Guess what?

That ice is made with the same undrinkable water!

And here's a tip: keep a bottle of water in the bathroom, or I guarantee you'll accidentally brush your teeth with the wrong water.

If you do order for raw fruits or vegetables, peel them yourself. Even five-star restaurants may have only one-star kitchen service. More adventurous eaters might bend the rules, especially when exploring local street food, but do so at your own risk!

So if you do get sick, there are simple ways to treat it. Over-the-counter medication like Imodium can be helpful in mild cases. But if you've contracted a bacterial infection or parasite, antibiotics are a better option. 

The biggest risk with stomach ailments is dehydration. Keep packets of oral rehydration salts, which should be consumed with plenty of clear fluids. If the symptoms persist, contact a doctor. As most travelers can attest, this common ailment has ruined many a vacation, so don't let it get worse before it gets better.

Sign up for the AARP Travel Newsletter.