The gallbladder extracts water from its store of bile until the liquid becomes highly concentrated. The presence of fatty foods triggers the gallbladder to squeeze its bile concentrate into the small intestine.
Gallstones (biliary calculi) are small stones made from cholesterol, bile pigment and calcium salts, usually in a mixture that forms in the gallbladder. Some things that may cause gallstones to form include the crystallisation of excess cholesterol in bile and the failure of the gallbladder to empty completely.
In most cases, gallstones don't cause any problems. However, you might need prompt treatment if stones block ducts and cause complications such as infections or inflammation of the pancreas (pancreatitis).
