Bile

Bile - A greenish-brown alkaline liquid secreted by the liver. Bile carries away waste products formed in the liver and also helps to break down fats in the small intestine for digestion.

The waste products in bile include the pigments bilirubin and biliverdin, which give bile its greenish-brown colour; bile salts, which aid in the breakdown and absorption of fats; and cholesterol. Bile passes out of the liver through the bile ducts and is then concentrated and stored in the gallbladder.

After a meal, bile is expelled and enters the duodenum (the first section of the small intestine) via the common bile duct. Most of the bile salts are later reabsorbed into the bloodstream to be recycled by the liver into bile. Bile pigments are excreted in the faeces. (See also biliary system; colestyramine.)