m&ms, I've always suspected that you and I have something very bizarre going on inside that is very similar. When I was in Bolivia in 2003, I had three weeks of just the most unbelievable D you've ever seen, I think my record there was like 35 times in one day, and it was never less than 25 times. It went away after those three weeks, but then came back...and went away...and came back. When I was in Africa in 2000, I had the same thing, except also had high fevers with the D; and in Africa it was confirmed that I had parasites.
Three years later, now, I still have profuse, watery D that comes in waves. I'll have it for a few days, then normal stools for a couple days, then D again. ALL parasite tests - even weird ones that they don't usually test for - come back negative. It is unbelievable. An infectious disease doctor I had said the parasites I had in Africa could have irrevocably altered my intestinal function forever and that could be why I have D. I don't think that's out of the realm of possibility!