If your cat has continued diarrhea, it could be from either an allergy to a certain food protein (IBD), or even worms. If kitty is an in-house cat, then worms would be hard to acquire.
I have been dealing with IBD this year. It was diagnosed this year, but the signs were present for a while.
However, Artie's symptoms were much different that those of your kitty.
Chicken seems to be a big culprit. I took that away, resulting in immediate cessation of vomiting.
Try a limited protein diet. Try grain free. See if that works. I would suggest to stay with one protein source for a bit. It takes time to work out of the system.
I think I would try the grain free first. It is easier to do than the limited protein. I do not know if you have availability to Natures Variety line of food. They are pretty good.
I may sound like a know it all, I apologize if I do. These are just some things I found out the hard way.
People here are great and have so much wisdom. I am just sitting here, drinking my morning coffee, and decided to join in and try to tell you what seemed to have worked for my guy.
You could also try a probiotic. You just open the capsule and add it to the food. If there is a chicken allergy, you have to be a bit careful with the kind of probiotic you use. If it states 'animal digest'", as in Forti-Flora, thean you do not know what kind of animal it is. it could be chicken, as far as you know. Artie's specialist recommends "Proviable" probiotic. I am not really certain if that has helped my guy. I am just relaying the information I was told.
I wish you luck in finding the culprit of the diarrhea. It take so much out of our little ones. if you find he is losing weight, then you need to take him to a Vet asap, for further testing. Even if your guy has a decrease in appetite.
oops!!!!! now after re-reading your post, I see you are doing a raw diet.. I cannot help there, but it could also be from a food allergy....I would try the probiotic....sorry for the mis post.....I apologize.