|Poo, Pills and Parasites by Cory Annis, MD; The Unorthodoc
Diarrhea: Boiled GREEN bananas are also good for treating diarrhea. (There is even research to support this, if anyone's into that). There are complex starches that act as "binders" in green bananas that degrade as the fruit ripens. Ripe bananas are still a good non-challenging food to eat when recovering from diarrhea. They just don't stop things up as much. Boil them in the skins for 10 minutes then cut off the top and squeeze out the innards. Cool and eat.
Culturelle (lactobacillus GG) is a stable capsule form of probiotic that travels well and can be swallowed whole or sprinkled on food. It helps restore "good" bacteria to a "scorched" colon, as does yogurt.
To prevent dehydration: If you cannot lay your hands on premixed rehydration fluid, try a 50/50 mix of boiled water (or tea) AND fruit juice (or sugared soda) with an added pinch of salt per glass. Plain water, even if clean, is not easily absorbed by an inflamed intestine and you will pass it on through or vomit it back. Salt and sugar, however, "trick" the intestine into letting the water into your blood stream. Drink enough fluid to pee 4 or more times in 24 hours, no matter what is coming out of you elsewhere. If vomiting, try to drink only a tablespoon (15 mL) every 5-10 minutes. If you go an hour w/o vomiting, increase to 2 tablespoons (1 ounce, 30 mL) every 10-15 minutes. After an hour, go to every 5 minutes for an hour. Drink naturally after that. If you do vomit, wait 30 minutes and start again at 15 mL (1 TBSP).
For nausea: Bonine (meclezine) which is available in any airport, will treat nausea, vertigo, motion sickness, and insomnia. It will make you sleepy,though, so be aware of your surroundings, your activity and your buddies. take anywhere from 12.5 to 50 mg every 6-8 hours, depending on the desired effect.
For constipation: Try plain magnesium tablets are very portable and cheap. Take 250-500mg once a day at bedtime. Prunes and pears are great natural sources of sorbitol. This also is the un-digestable sugar that serves as the sweetener in sugar-free (or "dietetic")hard candy(which makes a good portable laxative on it's own).
Magnesium is also a mild blood vessel relaxer, which may be how it helps ward off migraines and improves muscle cramps.