The goal of this observational, quality improvement study is to compare the effect of a dose of morphine given during gall-bladder removal surgery. The main questions to answer are: * Do participants, who are given given a dose of morphine during gall-bladder removal surgery, experience less pain after surgery? * Does a dose of morphine during gall-bladder removal surgery cause more side effects? The investigators will compare the effects of two types of anesthesia: a) anesthesia without morphine during surgery, and b) anesthesia with morphine during surgery.