My 18 year old was hyperthyroid controlled well with meds and my 17 year old also has IBD. She however, is a picky eater and won't do any any of the hypoallergenic foods so she gets a daily dose of steroids and is doing wonderful. First, for the IBD. Will she eat the hypoallergenic food? There are a number but you have to guess at the allergy because unless you have allergy testing, you aren't sure which component of the food they are allergic to. I would also consider a holistic vet and possibly a raw diet. There is a raw diet portion to this forum. For the hyperthyroid, my cat was on Methamazole (sp?).