Cholelithiasis, commonly conocidad as gallstones or gallstones, is the formation of stones in the biliary tract especially in the gallbladder. They are growths of solid materials that can have different sizes, even going to fill the bladder. Most of these stones are composed of cholesterol crystals, the remainder are gallstones consituyen mainly pgimentarios and bile pigments and other compounds. At the time gallstones starts producing symptoms in the patient resorts to a surgical treatment involving the extirpation of the gallbladder ( cholecystectomy ).