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 termedgallstone ileus.
Kidney stones, one of the most painful of the urologic disorders, have beset humans for centuries. Scientists have found evidence of kidney stones in a 7,000-year-old Egyptian mummy. Unfortunately, kidney stones are one of the most common disorders of the urinary tract. Each year, people make almost 3 million visits to health care providers and more than half a million people go to emergency rooms for kidney stone problems.
Most kidney stones pass out of the body without any intervention by a physician. Stones that cause lasting symptoms or other complications may be treated by various techniques, most of which do not involve major surgery. Also, research advances have led to a better understanding of the many factors that promote stone formation and thus better treatments for preventing stones.