Hi there. I don't know whether this will help or not, but a lot of your symptoms sounds like Celiac. I had my gallbladder removed and a couple of years later started having the same issues. For years. They finally did a blood test and endoscopy and found I have Celiac. One way to test it yourself, quit eating wheat products. It's a autoimmune disease, when you ingest wheat the body literally turns on itself. Causing abdominal pain, nausea, back pain, and upset stomach to name a few. Unfortunately Celiac can cause other problems. One being chronic pancreatitis. Which I also have. Again all the symptoms you describe. Have a ERCP done.