It sounds like those might be liver stones that you are passing. Sallybb passed them spontaneously while doing the Master-Cleanse a few months back. Have you seen the pictures here? Do they look like that? What color are they?
Sorry so many questions....
It is pretty common for there to be parasites embedded in the stones as well. The diarrhea very well could have been stagnant bile being released which would explain the nausea as well.