Cat with smelly poo issues...

Has anyone tried just treating the diarrhea? I don't have ANY experience with this and I'm on my second cat, but in horses, when they have diarrhea, we give them Pro-Bios and that tends to solve the problem. (I really don't know much about what it contains, but maybe they have something like that for cats?)

In this case, diarrhea is a symptom of another problem. So to treat the diarrhea is just covering up the actual problem. This cat may have some very severe allergies to food, or it may have IBD. Hopefully this new diet can help the cat, and ease the noses of her roommates. :)

I'm sorry, I can't really blame the vet for the eyes and sneezles, they keep things as clean as they can but cross contamination is not always 100% avoidable.