Hi, I am new and this is my first real post. My younger son can have no dairy. But my question is for my older son. He is multihandicapped. He has drank milk before, but recently he was put on Pediasure. He had a major allergic reaction to it. He also gets very ill after drinking Ya-hoo. My dr. said he thinks it may be casein. My question is, if he can't have casein, then how come he can drink milk and not get sick. Isn't casein in all dairy products? Especially milk?? Thanks all, Lila