What Causes Abdominal Pain After Eating?

Hello Dr Rynne, My daughter has been complaining of abdominal pain for several years after eating. There is often complaints of nausea and abdominal pain. She has been to a Gastroenterologist a couple of years ago and they ran blood tests and reported to find nothing. She continually is having stomach pain that is triggered by eating. An ulcer has been ruled out by her family physician. It is severe enough to bring her to tears at times. I am not sure what steps to take next. I know the Dr. has her on a stomach antacid that is of prescription strength. Her mom takes her to the Dr so I don t know what it is. I am at a loss to what to look at next. Tonight she went to dinner with me and she ate Japanese noodles, a little sushi, and she almost immediately began complaining of stomach pain and having nausea. As soon as we got home (about a fifteen minute drive) ran to the bathroom and had an episode of diarrhea. She has not vomited at this time although the nausea is severe. Can you give me some direction as what to do next? It is complaints of pain after eating almost anything and so she is not ever wanting to eat. Perplexed over the symptoms, and the fact the family doc can not seem to find out the cause has me lost. She said to me tonight I just don t want to be sick anymore!