The gallbladder serves the function of concentrating and storing bile, produced in dilute form by the liver, and secreting the bile through the cystic ducts into the duodenum where it can help in digestion. The gallbladder itself is a blue-green organ, about three inches long, located on the underside of the liver. Bile is composed of cholesterol, bile salts, and bile pigment. The gallbladder is not critical to the survival of the human and may be removed without severe adverse effects. The crystallization of the bile salts in the gallbladder gives rise to gallstones, which often requires surgical correction.