Most gallstones result from supersaturation of cholesterol in the bile, which acts as an irritant, producing inflammation in the gallbladder, and which precipitates out of bile, causing stones. Risk factors include gender (women four times as like to develop cholesterol stones as men), age (older than age 40), multiple parity, obesity, use of estrogen and cholesterol-lowering drugs, bile acid malabsorption with GI disease, genetic predisposition, rapid weight loss. Pigment stones occur when free bilirubin combines with calcium. These stones occur primarily in patients with cirrhosis, hemolysis, and biliary infections.
Acute cholecystitis is caused primarily by gallstone obstruction of the cystic duct with edema, inflammation, and bacterial invasion. It may also occur in the absence of stones, as a result of major surgical procedures, severe trauma, or burns.
Chronic cholecystitis results from repeated attacks of cholecystitis, presence of stones, or chronic irritation. The gallbladder becomes thickened, rigid, fibrotic, and functions poorly.
Complications of gallbladder disease include cholangitis; necrosis, empyema, and perforation of gallbladder; biliary fistula through duodenum; gallstone ileus; and adenocarcinoma of the gallbladder.
