re: spence987 said "...some bogus parasite called blastocystis..."
I would like to add, FYI from my experience, that most, about 80% of the time, that is true; blastocystosis is benign.
BUT there are some species, about 20%, that can cause just terrible dysentery, nausea, dehydration and other very severe symptoms. This severe form is not generally recognized by North American MDs.
How I know, is because I came back from Africa extremely ill to the point of jaundice with "blastocyst" as the only diagnosis. I was fortunate to find enough research to cure myself. Blastocystosis actually kills people in some African countries.