I have been battling the big "D" with my kitties and came across this warning link at ShowCatsOnline.com

It seems that the formula was changed in December 2003 and the new stuff has aspirin. Here is a clip:

The new formula of Kaopectate速 may be deadly to your cat.

Kaopectate速, the diarrhea medication for humans, has also been used effectively on cats and dogs.

However, Kaopectate's速 new formulation contains bismuth subsalicylate, an aspirin derivative that may be harmful to some dogs and can be deadly to cats