From the description you've given (pain under the right side rib cage, and a knot that moves and causes pain and burning under the skin), and since the gall-bladder is removed, it's possible that your friend is experiencing lipoma, which is a collection of fat cells into a ball. A lipoma is a benign tumor that usually doesn't need to be removed except when they create pain or get larger. Liver problems might also be taken into consideration, but they also cause nausea, vomiting, dysfunction of the liver enzymes. The best way to solve the problem would be to request a biopsy of the knot, so that, after seeing the tissue under microscope, the right diagnosis could be made. You friend can seek an opinion from an internist or her general practitioner for a preliminary exam and a referral.