well, you will need to stay with low carb wet food for sure - I have to avoid wet food with caraggeen and the various gums (guar gum for example) as these can really aggravate my cat's IBD and pancreatitis. High fat also seems to set off symptoms. And many will recommend wet food with novel proteins (rabbit, venison, duck) There is a ton of great information about food on the website www.ibdkitties.net- ibdkitties also has an active Facebook site
I'm sure others here have ideas as well