So...with any stretch of the imagination (cut open one of your digestive enzyme pills)...could the white things be bits of those pills clumped together to form bigger lumps?
If there is NO way that they could be your digestive enzyme pills (interesting...because if you don't have enough digestive enzymes to digest food...you may not be able to digest the pills either - wouldn't that be a Catch-22!) - then we have to assume that you're actually flushing out some sort of stone! Have you kept any (in the freezer)...
I wish you could take a picture for us to see!
*I'm crossing my fingers that they're stones, Marg!