A gallstone is a stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to the presence of migrated gallstones within bile ducts. Most people with gallstones (about 80%) are asymptomatic. However, when a gallstone obstructs the bile duct and causes acute cholestasis, a reflexive smooth muscle spasm often occurs, resulting in an intense cramp-like visceral pain in the right upper part of the abdomen known as a biliary colic (or "gallbladder attack"). This happens in 1–4% of those with gallstones each year. Complications from gallstones may include inflammation of the gallbladder (cholecystitis), inflammation of the pancreas (pancreatitis), obstructive jaundice, and infection in bile ducts (cholangitis). Symptoms of these complications may include pain that lasts longer than five hours, fever, yellowish skin, vomiting, dark urine, and pale stools.Risk factors for gallstones include birth control pills, pregnancy, a family history of gallstones, obesity, diabetes, liver disease, or rapid weight loss. The bile components that form gallstones include cholesterol, bile salts, and bilirubin. Gallstones formed mainly from cholesterol are termed cholesterol stones, and those formed mainly from bilirubin are termed pigment stones. Gallstones may be suspected based on symptoms. Diagnosis is then typically confirmed by ultrasound. Complications may be detected using blood tests.The risk of gallstones may be decreased by maintaining a healthy weight with exercise and a healthy diet. If there are no symptoms, treatment is usually not needed.
The lack of a gallbladder has no negative consequences in most people, however 10 to 15% of people develop postcholecystectomy syndrome, which may cause nausea, indigestion, diarrhea, and episodes of abdominal pain.There are two surgical options for cholecystectomy:

Open cholecystectomy is performed via an abdominal incision (laparotomy) below the lower right ribs. Recovery typically requires 3–5 days of hospitalization, with a return to normal diet a week after release and to normal activity several weeks after release. Laparoscopic cholecystectomy, introduced in the 1980s, is performed via three to four small puncture holes for a camera and instruments. Post-operative care typically includes a same-day release or a one-night hospital stay, followed by a few days of home rest and pain medication. Perforation of the gall bladder is not uncommon—it has been reported in the range of 10% to 40%. Unretrieved gallstone spillage has been reported as 6% to 30%, but gallstones that are not retrieved rarely cause complications (0.08%–0.3%).Obstruction of the common bile duct with gallstones can sometimes be relieved by endoscopic retrograde sphincterotomy (ERS) following endoscopic retrograde cholangiopancreatography (ERCP). Medical
The medications ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) have been used in treatment to dissolve gallstones. A 2013 meta-analysis concluded that UDCA or higher dietary fat content appeared to prevent formation of gallstones during weight loss. Medical therapy with oral bile acids has been used to treat small cholesterol stones, and for larger cholesterol gallstones when surgery is either not possible or unwanted.