People get traveller's diarrhea by eating food and drinking water that contain germs.
People can get this illness in areas of the world where drinking water is not clean. Cooks and food handlers may have on their hands the germs that cause traveller's diarrhea, but they may not get sick themselves. In the same way, people who live in the same place often drink tap water that contains these germs, but they do not get diarrhea. This is because their bodies are used to the germs. Do not drink bottled water if the seal on the bottle has been broken.