[header] How to avoid having diarrhea during travel [title] Do not drink water that hasn't been sterilized. [step] Tap water and well water aren't treated in developing nations the same way they are in developed nations. This means that diarrhea-causing microbes are often present. 
Stick to bottled water rather than water from a tap or well whenever possible. [substeps] If you must drink water from a tap, then you should sterilize the water by boiling it for at least three minutes (five minutes if using it to mix baby formula).