This whole thing started with the diet change. Diarrhea was never a problem
before the diet change. Maybe it's a food alergy, I don't know.

So your cat didn't have a problem until you started feeding him the urinary
formula of Science Diet? Interesting. Maybe he is allergic to something in
the Hill's foods, I don't know.

Lauren, you're first suggestion is always a problem w/ Hill's, isn't it? Lay
off it for awhile if you can help yourself. If it is a food allergy, z/d would
diagnose it fairly quickly and also be the long-term solution. Oops, never
mind--it's a Hill's diet that works.