Bile

About the Bile

Bile is a yellow green fluid produced continuously by liver cells, stored and concentrated in the gallbladder, and released into the duodenum when fatty food enters the intestine, in response to the hormone cholecystokinin. Its main components are water, bile salts, cholesterol, phospholipids, bilirubin, and electrolytes. Bile salts act as detergents, breaking large fat droplets into smaller ones and forming micelles that allow fats and fat soluble vitamins A, D, E, and K to be absorbed. Most bile salts are reabsorbed in the last part of the small intestine and returned to the liver, a recycling loop called the enterohepatic circulation. Bile is also the main route for excreting bilirubin, the breakdown product of hemoglobin from old red blood cells, which gives stool its brown color, as well as excess cholesterol and some drugs. An imbalance in the components of bile can lead to the formation of gallstones, and blocked bile flow leads to jaundice and pale stools.