Gallstones may form if bile contains too much cholesterol, too much bilirubin, or not enough bile salts. Researchers do not fully understand why these changes in bile occur. Gallstones also may form if the gallbladder does not empty completely or often enough. Symptoms may include sudden and rapidly intensifying pain in the upper right portion of your abdomen, sudden and rapidly intensifying pain in the center of your abdomen, just below your breastbone, back pain between your shoulder blades, pain in your right shoulder, nausea or vomiting. These stones can cause pain and other complications. Treatment options often involve minimally invasive surgery to remove the gallstones, and sometimes the gallbladder.