I'd say to let his digestive system mature (for some dogs it takes up to two years... then it gets much better all by itself) and feed as well as you can in the meantime
have you tried giving him a broad-spectrum digestive enzyme before his meals with "healthy additions"? it can help more than you think!
hang in there... we've been there and done that with our boy, some days i was close to tears with frustration and running the food wheel (kibble, cooked, raw, meds, pills, you name it). What finally worked for him was the complete cessation of any and all commercial food. a 24 hour fast and only raw from then on, in the beginning with digestive enzymes and probiotics. now he has such perfect poops it makes you want to take a photo, LOL!
he can eat just about anything and everything and be totally ok (well as long as it's not kibble. both my dogs get very sick on it...).
i wish you luck... i know it's frustrating as h3ll!!
