biliar

Biliar, or biliary, refers to the bile and the biliary system, including the liver, gallbladder, and the network of bile ducts. Bile is produced by hepatocytes and drained into intrahepatic ducts, then via the hepatic ducts to the common hepatic duct. The gallbladder stores and concentrates bile, releasing it into the duodenum through the cystic duct and the common bile duct after meals, under control of cholecystokinin and the sphincter of Oddi.

Bile contains bile acids, cholesterol, phospholipids, bilirubin, and electrolytes. Its primary role is emulsification of fats and formation of micelles for lipase action. Bile acids are circulated back to the liver through the enterohepatic circulation, helping maintain a pool of bile acids for digestion.

Common biliary disorders include cholelithiasis (gallstones), cholecystitis (gallbladder inflammation), choledocholithiasis (bile duct stones), cholangitis (bile duct infection), biliary atresia (a neonatal condition), and cholangiocarcinoma (bile duct cancer). Symptoms may include right upper quadrant pain, jaundice, and abnormal liver tests. Obstruction of bile flow can impair digestion and liver function.

Diagnosis typically begins with abdominal ultrasound and liver function tests. Advanced imaging such as MRCP or ERCP may assess the ducts and allow intervention. Treatment ranges from observation for asymptomatic stones to cholecystectomy for symptomatic gallbladder disease; endoscopic stone extraction or stenting via ERCP; and ursodeoxycholic acid in selected cases. Acute cholangitis requires antibiotics and biliary drainage.