Actually, the diarrhea can be a defense mechanism to attempt to flush out the toxins. If it were me, for now, I would remove all extra forms of fiber, including pumpkin, and anything else that could slow the transit time through the digestive tract, so the toxins aren’t retained any longer than necessary.
Probably, amongst other things, the outside lab is testing for the various toxins that some clostridium species create under certain conditions.
For now, and temporarily, I would just go with lightly cooked beef, chicken, and plain white rice (most white rice sold in the U.S. is enriched with vitamins). I wouldn’t use any whole grains or anything else hard to digest.
