Incidence of gallstone is high in

Pathogenesis of cholesterol Gallstones Cholesterol is insoluble in water (water is major constituent of bile, 85-95%) Bile acids and phospholipids in bile keep cholesterol in solution by the formation of micelles An excess of cholesterol relative to bile acids and phospholipids allows cholesterol to form crystals and such bile salts is called lithogenic or supersaturated bile Factors responsible for formation of gallstones Lithogenic bile Increased biliary cholesterol--Obesity, cholesterol rich in diet, clofibrate therapy Decreased Bile acids - Primary biliary cirrhosis, OCP's, mutation of CYP7A1 gene, impaired enterohepatic circulation of bile acids (Ileal disease resection, cholestyramine or colestipol) Decreased Biliary Lecithin - MDR-3 gene mutation leads to defective secretion in bile Nucleation Cholesterol monohydrate Crystal aglomerate to become macroscopic crystal by nucleation Pro-nucleating factors - Mucin, Non-Mucin, Infection Anti-Nucleating factors - Apolipoprotein A-1 and A-II Excess of Pro-nucleating factors or deficiency of Anti-Nucleating factors results in formation of gall stones Stasis or GB hypomotility Prolonged TPN Prolonged fasting Pregnancy Octreotide OCP's Massive burns Ref: Sabiston 20th edition Pgno : 1492