My son has been on rice and oatmeal cereals for almost 2 months but lately he has been having trouble with it. When I try to feed him he grunts and refuses to eat but when I feed normal baby foods he will eat normally. I took him off of the cereal for a week or so and then tried it yesterday. He ate OK but has had burps and toots since then. Is this because of the cereal? And how important is it that he gets cereal?