My son has had problems with stomach pain all his life. We found that if he sucked on a di-gel or rolaid, the pain went away. That was my brother, the gastroenterologist's idea. He said rather traumatize the child diagnosing the problem, just treat it with an over the counter medication. If it worked, great. If not, we could always do the scoping. He didn't get scoped til this year at 24.
