Gallstones are extremely common, as many as twenty per cent of the UK population may get them during their life time. Most people with gallstones get no symptoms and need no treatment.

Gallstones are usually made from cholesterol or bile pigments, both of which are normal constituents of bile. They may develop for several reasons, either because of an excess of one or other constituent in the bile or because the gallbladder is not emptying properly thus allowing sediment to form or because there are abnormal proteins in the bile triggering precipitation of cholesterol or pigment stones.

Most stones are just a few millimetres across although occasionally they may reach 4-5cm