Still happy but not so fat

Devin went in for his 9 month well child last week and it was definitely not one of our best visits. Poor little guy hasn't grown since his six month appointment. He put on a whopping 6 ounces. I knew he was getting skinnier and I was crying that his skin didn't look like it was going to pop any more and that I could tell he had a neck, and I worried that he seemed soooo interested in food but wasn't (isn't) the champ eater I thought he would be, but I didn't expect no growth. Oh, and he has on and off diarrhea that concerned me also. The two might be related--food allergy?? It has yet to be determined. The upshot is that my concerns that I attributed to being an overly concerned parent were validated. His poop situation is not normal. His growth situation is not normal. I have yet to have his lack of food intake validated though. The doc thinks that he's getting enough food into his body but that he can't use it correctly. However, if I were going to make a prediction, I would guess there is some kind of food allergy going on (but not gluten or milk), and that there is something going on with his mouth also. Reason being he used to let his mouth hang open with his tongue hanging out like a puppy dog. Reason two being that he pockets food (the food sits in his cheeks like a chipmunk for a while before he can figure out how to swallow). Reason 3 he seems way too interested in food and previously was growing fast enough that what he intakes doesn't seem to be enough to me. For the meantime I've added Pediasure to his diet and I'm nursing him at night when he wakes up and hoping that will do some good until the root cause is addressed. Things to be grateful for: he is still the world's happiest baby and Mike made an awesome candy cane shaped stromboli for thanksgiving dinner b/c I was too fixated on Devin to do anything!!