If you are getting another endoscopy anyway, ask them to take a biopsy and check for celiac. I had my gallbladder taken out but it wasnt until a couple of years later that i found out i had celiac and then after being gluten-free my weird stomach pains went away. Most drs dont test for it rountinely..
Not likely that you have a serious problem of the pancreas. It sounds like typical gallbladder to me. And there are many people, even on these boards, who are like myslf and have these symptoms because of a gallbladder that doesn't have any stones in it. Ask about having a HIDA scan - it tests the function of the gallbladder and shows whether it's working properly or not. Pancreas problems, which are in that middle location you are talking about, are usually caused by gallbladder problems. I've had pancreatitis several times in the past 4 years without stones - just sludge, which doesn't show up on an ultrasound.