What are Gallstones and Gallbladder Disease?
Gallstones are formed from bile, a fluid composed mostly of water, bile salts, lecithin, and cholesterol. Bile is first produced by the liver and then secreted through tiny channels within the liver into a duct. From here, bile passes through a larger tube called the common duct, which leads to the small intestines. Then, except for a small amount that drains directly into the small intestine, bile flows into the gallbladder through the cystic duct. The gallbladder is a four-inch sac with a muscular wall that is located under the liver. Here, most of the fluid (about two to five cups a day) is removed, leaving a few tablespoons of concentrated bile. The gallbladder serves as a reservoir until bile is needed in the small intestine for digestion of fat. When food enters the small intestine, a hormone called cholecystokinin is released, signaling the gallbladder to contract. The force of the contraction propels the bile back through the common bile duct and then into the small intestine,
