I have recurring, severe upper abdominal pain. It appears to be brought on by foods but I can t determine which foods specifically. I can eat something multiple times and not have any pain and then other times I will feel pain almost immediately after eating. I have determined that raw broccoli and mushrooms almost always cause pain, so I have avoided them for them years. However, recently, I have had a few incidents where the pain starting after eating eggs but I have eaten eggs hundreds of other times with no pain. I also had a very bad flare up the other day after drinking a protein shake. Again, I have had many of these shakes before with no problem, so now I m thinking maybe the cause is not food related? The pain is a severe burning sensation in the center of my upper abdomen, right under my breast bone. The pain stays for hours and with the pain, I will sometimes have nausea but no vomiting.