I have a dog with colitis, what food can you recommend?

Maybe you could use Chappie in conjunction with something else. I wonder what a mix of Chappie and Applaws would do. Otherwise look at the ingredients in Chappie and see how it's different from other foods. There may be an ingredient or two that doesn't agree with him, and Chappie doesn't have it. If you can find another food with similar ingredients, it may work. Also you could look into adding probiotics to his diet. They help keep the digestive tract in line. Good for any dog but especially one with issues.. Good luck!