To prevent diarrhea, avoid tap water unless it has been boiled, filtered or chemically disinfected (with iodine tablets). Eat only fresh fruits or vegetables if they are cooked or if you have peeled them yourself and avoid dairy products that might contain unpasteurised milk. Buffet meals are risky since food may not be kept hot enough; meals freshly cooked in front of you in a busy restaurant are more likely to be safe.
If you develop diarrhea, be sure to drink plenty of fluids, preferably and oral rehydration solution containing lots of salt and sugar. A few loose stools don't require treatment, but if you start having more than four or five motions a day, you should start taking an antibiotic (usually a quinolone drug) and an antidiarrheal agent (such as loperamide). If diarrhoea is bloody, persists for more than 72 hours or is accompanied by fever, shaking chills or severe abdominal pain, you should seek medical attention.