He is not taking any medication that would cause him stomach upset. The only thing he is taking is Flagyl. We have tried the Vitamin-B with little effect. There is nothing going on in his mouth as we have checked that very carefully and he is only 18 months old so he teeth are great. We haven't done an ultrasound, but no he isn't in pain or appears uncomfortable after he eats. In fact when he finally does he eat seems happy and content. I don't know what we will do from here. Once again he wouldn't touch any food last night or this morning. It is so frustrating to watch him not eat when he has access to so much good food. :(