Since you should probably ask your doctor anyway go ahead and ask him or her. We will only say that as long as you boil the water you will be safe. The local 'bottled' water that restaurants will try to serve you is often just filtered from the Nairobi taps, so don't think you are always drinking the 'pure springs of Mt. Kenya.' It is a pretty good bet that you are not. Order bottled soda water or stick with soft drinks. On the other hand if you are trying to avoid a case of The Kenya Two Step, you are wasting your time. All salads, cutlery and glasses are washed in tap water and it only takes one little microbe. Not to mention ice cubes. On a trip to Kenya, as with a trip almost anywhere in the world, travelers diarrhea is bound to get you . Its just a change in the bacteria in the water per se and it only lasts about a day anyway. Take your Pepto and you'll be fine. Or better yet, take nothing and just let your system do what its trying to do and you'll be just as fine. And probably sooner. So try to be careful but don't drive yourself crazy watching where every drop came from. You might not know where it came from but you will certainly know where it will end up.