After Having My Gall Bladder Removed 25 Years Ago Open

After having my gall bladder removed 25 years ago open surgergy) 2yrs ago i had a 6mm cholestesterol stone stuck in the cbd! I had an ercp and the duct opening cut/made bigger to stop this happening again, but since this op I get jumping/conractions after eating or if I'm Hungry. (In upper abdomen.) Worse if lying down on my side? Is undiluted bile causing this or nerve damage? doc said try omaprazole but not acid I'm sure. Didnt stop it. Any ideas? Thankyou.