Welcome to the gastroenterology community? Does the pain always correlate with eating?
If there's no mental involvement here, this is something that you need to discuss further with a specialist. An ER is no place for a detailed diagnosis- they're mostly technicians and mechanics there. You could ask about allergic reactions or a hundred other things, but best bet is to see a new specialist and try to get a fresh perspective, in my opinion. Regardless, this is a medical issue, and one you shouldn't be attempting to diagnose yourself.