Dull Aching Pain on Back Behind Gallbladder and Liver

Hi Folks. I'm experiencing a dull ache, almost throbbing pain on my back. It's almost directly behind my gallbladder and liver. What's going on? Is my gallbladder trying to pass a stone or is the bile moving down the bile duct or am I experiencing spasms due to blockage? I noticed that this usually happens after I eat. I tried the cleanse last weekend with mixed results. Based on this aching pain, which I think is due to the gallbladder, I'm going to try the cleanse again (yes, I know it's suppose to be two weeks). If anyone could shed some light on what's going on with my body, I would appreciate it. Thanks.