What is Gallstone?
A gallstone, also called a cholelith (), is a calculus (stone) formed within the gallbladder as a concretion of bile components. Lithiasis (stone formation) in the gallbladder is called cholelithiasis (). Gallstones are formed in the gallbladder but may pass distally into other parts of the biliary tract such as the cystic duct, common bile duct, pancreatic duct or the ampulla of Vater. Rarely, in cases of severe inflammation, gallstones may erode through the gallbladder into adherent bowel potentially causing an obstruction termed gallstone ileus.
Presence of gallstones in the gallbladder may lead to acute cholecystitis, an inflammatory condition characterized by retention of bile in the gallbladder and often secondary infection by intestinal microorganisms, predominantly Escherichia coli, Klebsiella, Enterobacter, and Bacteroides species. Presence of gallstones in other parts of the biliary tract can cause obstruction of the bile ducts, which can lead to serious conditions such as ascending cholangitis or pancreatitis. Either of these two conditions can be life-threatening and are therefore considered to be medical emergencies.