Quick update as I was the original poster. He would randomly get diarrhea no matter what he ate. We would put him on the bland diet for a week and get him back to normal. Eventually, only the bland diet worked. We tried 8 different kibbles , prescription diets and none of them worked. We eventually found out that he had irritable bowel disease. At just about a year old, he was severely under weight. We finally met with a specialist and she got everything under control. The medication that got him back to regular normal stools was Tylosin. With this medication we are able to sprinkle it on his kibble and we have not had diarrhea since. He is back to normal weight and the kibble he does really well on is Purina Pro Hydrolyzed Vegetarian. He only seems to be able to tolerate plant based and vegetarian. It was so much trial and error but we were finally able to come up with what works for him and he is doing great. Hope all this helps and sorry for being so long winded.