Poison or Burning Water Borne Bugs
While working for a parrot sanctuary, we used to put drops of what was essentially grapefruit extract into the water to purify it and keep bacteria from growing. It would actually keep the water bowls from getting slimy and dirty after the parrots dunked their food or bathed in it.
I think this may work, but in too large amounts than would be worth it. Your water will always be lemony fresh and juicy afterwards.
...From the US FDA Website:
“…Grapefruit seed extract is reported to be inhibitory to a number of human pathogens. There has been evidence, however, that any antibacterial activity of commercial preparations is due to the various preservative agents (triclosan, methyl parabene, benzethonium chloride) contained within the product. Researchers have found that products not containing any preservatives and several self-made preparations had no antimicrobial activity (Woedtke and others 1999). In the aforementioned study by Lee and others (1998), the composition of the GFSE incorporated in the film was not discussed or examined. It is obvious that if pure GFSE is to be used, its antimicrobial properties will have to be fully investigated. If the active antimicrobial ingredients in commercial GFSE preparations are preserving agents, they may be better targets for investigation.”
Excellent Resource for all Q/A:
--We used the 4oz dropper bottles of concentrate.
You probably picked up a parasite, very likely when you were in Africa. Since you complain of intestinal problems please know that one and a half billion people in the world have round worms and many millions tape worms both of which reside, at least in part, in the intestine.
You could have picked up the first from a mouthful of water even in the shower and both could have come from something as simple as a salad or undercooked food. (Or even a fly that 'stood on shit' and then on your food.)
It does not sound like Giardia whose intense cramps/runs leaves you no doubt when you are heavily infected.
The problem with both Grapefruit seed extract and especially citric acid is that they are both well absorbed by the stomach so they will literally go around the infection. Grapefruit seed extract is only moderately potent.
An old cure for intestinal worms calls for a handfull of papaya seeds but that has been replaced by modern medicine.
The best cure for both round worms and tape worms is probably a single dose of albendazole http://en.wikipedia.org/wiki/Albendazole or Praziquantel but it is mainly for tapeworms and may have little effect on round worms.
The best for treating a broad range of intestinal worms, which is used a lot, is albendazole combined with Ivermectin. About 50 studies on infected Guatemalan school children using this combination have been made. Just google 'guatemala' 'albendazole' and 'Ivermectin'.