I had a HIDA scan with CCK and my ejection fraction was 16%. They advised me to have my gallbladder removed. I was having mid-back pain, sometimes on my right side, and trouble with indigestion and some nausea. No stones.
I recovered from the surgery more or less in a week (first 3 days were killer).
The pain I was having before started up again as soon as I could differentiate it from the post-surgical pain. And now it seems worse than before.
EGD test for ulcer was negative, as were other tests for pancreas disorder.
I'm going in for an ERCP as soon as they can schedule me. Dr. thinks my symptoms suggest Sphincter of Oddi Dysfunction.
I also from time to have have epigastric/chest pain and pain between my shoulder blades -- so bad on one occasion that I went to the ER. All tests came back normal.
Having your gallbladder removed, assuming you have no stones, is unlikely to completely cure you, in my own "lay" opinion. The problem may be more generally with your duct system... But I will say that the indigestion and nausea I was experiencing are more or less gone; just left with the pain.
My best advice: find a doctor who is willing to see this through with you. Keep searching. I finally found one, and that right there made me feel better. First doctors I saw after my surgery wanted to write me off to "IBS" and put me on anti-depressants. I know the pain I'm having is not classic IBS pain, and my current doctor has confirmed that.