Bile is a digestive juice produced by the liver and stored in the gallbladder. It functions to emulsify fats to aid digestion and absorption, excrete waste, and regulate gastrointestinal pH. Bile is composed of bile salts, bilirubin, cholesterol, and other components. It is secreted into the small intestine in response to food and aids fat digestion through emulsification. Unabsorbed bile salts undergo enterohepatic circulation to be reused. Gallstones may form if bile components precipitate from changes in composition.