As a part of the biliary tree, the gallbladder plays an important role in digestion, particularly the digestion of fats. Though some consider the gallbladder to be a non-vital organ, when it is congested or after a cholecystectomy, its essential function will have to be absorbed by other organs, in turn putting strain on their primary functions. For symptoms of abdominal pain, pain in the right shoulder, belching, sour taste in mouth, intense headaches, nausea, constipation, and clay-colored stools.