Gallstones (Cholelithiasis)

Key points

• • Gallstones are solid lumps that form in the gallbladder when the substances in bile fall out of solution, mainly cholesterol or bile pigment.
• • Cholesterol stones, the commonest in many countries, form when bile holds too much cholesterol, and their risk factors are remembered as the four Fs: Female, Forty, Fat and Fertile.
• • Pigment stones are made largely of calcium bilirubinate and other calcium salts, and form when there is too much pigment, as in the increased red-cell breakdown of haemolytic anaemia.
• • Many gallstones cause no symptoms, but a stone can block the outlet and cause severe pain after fatty meals (biliary colic).
• • A stone that blocks the cystic duct can cause inflammation of the gallbladder (cholecystitis), and one that blocks the bile duct causes jaundice.
• • A blocked bile duct can also inflame the pancreas (gallstone pancreatitis), because the two ducts share a common opening.