Eat (yes, eat) a cigarette, works for constipation, also cleans out intestinal parasites. Charcoal, powdered and mixed with water, then drank works pretty well for most cases of internal poisoning. Plantain (the green weed, not the banana like fruit), stewed and eaten is good for just about anything that ails you. There are a lot more "wilderness" fixes, as a start, I'd reccomend Chris Jankowski's book, "Wilderness Survival" as a good place to start reading.

Troy