Psyllium fiber is inexpensive and amazingly versatile. Not only can it control both constipation and diarrhea, it can help heartburn, too.
Can coffee cup lid contamination spread disease? There's been an uptick in norovirus on cruise ships this year. Beware the STOMACH VIRUS!
Can Pepto Bismol prevent or treat traveler's diarrhea? Some careful planning in advance can spare you a lot of digestive distress later on.