I found this book to be very helpful and informative, with tips on staying healthy as well as a frank but entertaining look at the various ways people set up toilet facilities worldwide.
There’s no way, and probably no good reason, to be subtle about it — diarrhea, parasites, and other gastrointestinal unpleasantries can be part of the price travelers pay for trying to see the world. Fortunately, this frank, witty guide lets world-explorers fight back against their invisible assailants. A noted traveler and writer, Dr. Wilson-Howarth explores such issues as sanitizing unhealthy water, safely consuming exotic foods, avoiding dehydration, keeping good hygiene on the road, and immunization.