Ask your vet about switching Shai to a senior food. It is more easily digested, but retains the fiber content needed for good bowel action. We've never had the cholitis, but my daughter adopted a dog that had severe gastritis. Ella was nothing but skin and bones when Charity adopted her and the vet didn't even think Ella would survive. Charity added (God, I'm having a major brain fart here) the nutrition supplement Nutri-something, comes in a tube like toothpaste. Anyway, Miss Ella is 6 years old and weighs about 50 lbs. and looks great, so there is hope for severe gastritis. Good luck with Shai.