my grandson is having severe stomach pain, the pain is any time before or after he eats anything, his pain goes all over his tummy, then later he ll be normal, we went to the doctor yesterday he put him on zantac and elixir. I am waiting for the P. A. to call me. What I want to know is how along does it take for the medicine to start working, he wants to go to school, he loves school he gets good grades, we asked him if there was anyone bothering him, he said no, that he has lots of friends. I m driving myself crazy I don t know what else to do.