I should have added that after the six weeks of strict diet after the loose yellow BM had stopped, I gradually went back to my regular diet; I very slowly added the things I used to eat, fruit, grain (mostly rice), milk, yogurt, etc. To my astonished relief, the blastocystosis symptoms were gone and never returned.
It sounds improbable, but I'm certain I gradually expelled it by eating foods it doesn't like/won't grow on.
I hope someone somewhere is doing research on the severe form of blastocystosis. It's very, very nasty. At one point I was taking bottles of water to bed with me, as I was too weak to get up.
And most Docs don't believe it can make you sick. Appalling.