Call or visit your doctor or travel nurse. He can offer you a prescription for an emergency medication you can take in case traveler's diarrhea strikes. Keep it in your carry-on for the return flight.
Pack Pepto-Bismol (or other bismuth subsalicylate). Consumed before every meal, this helps prevent your system from absorbing potentially harmful bacteria. The tablets are more effective than the liquid and are easier to pack.
Pack Imodium if you didn't get a doctor's prescription. Traveler's diarrhea should clear up within three days, but if you don't want to wait it out, you'll need a half dose of Imodium, followed by another in 24 hours.
Don't drink unbottled water; don't even brush your teeth with it. Most restaurants will open the bottle in your presence so that you can verify that it was sealed; if they do not, ask them to bring a fresh bottle. Wherever you purchase water, verify the seal.
Purified ice comes in a round form with a hole in the middle. If your ice is not purified, remove it immediately or send the drink back and ask for no ice, unless you're at a resort hotel or a very nice restaurant that caters to American tourists. Blended ice beverages are always a no-no.
Stay away from porous produce such as strawberries or lettuce as they absorb a lot of bacteria. Peeled fruit should be fine if the preparation conditions are trustworthy. If you need to peel your own fruit, be sure to not touch the inside flesh while peeling, then wash your hands thoroughly before consuming. Avoid fruit or vegetable juice except at resorts or nice restaurants.
Don't eat undercooked meat or seafood or anything that may have been prepared in unsanitary conditions. Avoid dairy products unless you can verify that they've been pasteurized.
Beverages that are safe include anything served very hot (like tea or coffee), carbonated beverages, sealed water bottles or alcohol (including beer and wine).
Eat bland starchy foods, such as plain tortillas.
Drink plenty of water to prevent dehydration. Avoid caffeinated drinks.
Continue to take Pepto-Bismol with every meal. Use the Imodium or doctor's prescription if necessary.
