Evan Ravitz has a knoll about curing parasitical infections naturally with Quassia, which contains the "phytochemical quassin, the bitterest substance found in nature."
People traveling in 3rd world countries are often afraid of intestinal parasites, but, having lived for 3 years in poorer areas of Mexico and 2 in Guatemala, I learned there are easy solutions. I picked up amoebic dysentery several times while on long bicycle trips, and knowing how to deal with them, I was able to continue with no problems. This method is for healthy people only!
Here's how I do it: If my gut hurts, I wait two days. If it's just a bacterial infection, you should start to feel better. Coconut milk is very soothing. Definitely avoid alcohol and sweets, which bacteria and other parasites love.
If after 2 days, you feel as bad or worse, you should start treatment with a "full-spectrum antibiotic" -or the herb Quassia, which is used in much the same way -especially if there is mucus in your feces and sulphur in the gas you pass.In most of Latin America, just go to a Pharmacia and ask for Flagyl (or the generic Metronidazole), the cheap drug available everywhere or say "tengo amebas" ("I have amoebas") and they'll almost certainly give you Flagyl. In the U.S. you need a prescription, so DON'T WAIT until you return or you'll have to pay for expensive tests to get treatment -while the amoebas are eating your lunch, dinner and breakfast and you are getting weaker.
Quassia won't make you feel as bad as Flagyl, but neither is fun. Both are killing everything in your gut, so you need to replenish the beneficial bacteria with probiotics, like yoghurt, kefir, sauerkraut, miso, etc., after the treatment.
Often people with amoebas will wait longer until they're really sick and go to a doctor for a stool test. If they don't find the amoebas with a microscope the first time, and you wait longer, it will take weeks or more to recover your strength after you take the treatment. That's why I assume I have them if I don't feel better in 2 days. Neither treatment is pleasant, but you'll function fine, which is nearly impossible with amoebas.
Quassia is available at herb and health food shops. It will be either shredded or chopped. Take a large handful on your trip, which should cost a few bucks.