What causes gallstones?
The gallbladder is about 3 inches long and stores and releases bile into the intestine to help digestion. Bile is a liquid made by the liver. It contains water, cholesterol, bile salts, fats, proteins, and bilirubin, a bile pigment. During digestion, the gallbladder contracts to release bile into the intestine where the bile salts help break down fat. Bile also dissolves excess cholesterol. Gallstones may form in one of three ways: when bile contains more cholesterol than it can dissolve, when there is too much of certain proteins or other substances in the bile that causes cholesterol to harden, or when the gallbladder does not contract and empty its bile regularly. Gallstones are clusters of solid material that form in the gallbladder. They are made mostly of cholesterol. Gallstones may occur as one large stone or as many small ones. They vary in size and may be as large as a golf ball or as small as a grain of sand. Experts have estimated that between 16 to 22 million people in the
