Cholangitis: Inflammation of the biliary ductal system (BILE DUCTS); intrahepatic, extrahepatic, or both.Cholangitis, Sclerosing: Chronic inflammatory disease of the BILIARY TRACT. It is characterized by fibrosis and hardening of the intrahepatic and extrahepatic biliary ductal systems leading to bile duct strictures, CHOLESTASIS, and eventual BILIARY CIRRHOSIS.Cholangiopancreatography, Endoscopic Retrograde: Fiberoptic endoscopy designed for duodenal observation and cannulation of VATER'S AMPULLA, in order to visualize the pancreatic and biliary duct system by retrograde injection of contrast media. Endoscopic (Vater) papillotomy (SPHINCTEROTOMY, ENDOSCOPIC) may be performed during this procedure.Liver Cirrhosis, Biliary: FIBROSIS of the hepatic parenchyma due to obstruction of BILE flow (CHOLESTASIS) in the intrahepatic or extrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC; BILE DUCTS, EXTRAHEPATIC). Primary biliary cirrhosis involves the destruction of small intra-hepatic bile ducts and bile secretion. Secondary biliary cirrhosis is produced by prolonged obstruction of large intrahepatic or extrahepatic bile ducts from a variety of causes.Bile Ducts: The channels that collect and transport the bile secretion from the BILE CANALICULI, the smallest branch of the BILIARY TRACT in the LIVER, through the bile ductules, the bile ducts out the liver, and to the GALLBLADDER for storage.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Cholagogues and Choleretics: Gastrointestinal agents that stimulate the flow of bile into the duodenum (cholagogues) or stimulate the production of bile by the liver (choleretic).Bile Ducts, Intrahepatic: Passages within the liver for the conveyance of bile. Includes right and left hepatic ducts even though these may join outside the liver to form the common hepatic duct.Cholangiography: An imaging test of the BILIARY TRACT in which a contrast dye (RADIOPAQUE MEDIA) is injected into the BILE DUCT and x-ray pictures are taken.Ursodeoxycholic Acid: An epimer of chenodeoxycholic acid. It is a mammalian bile acid found first in the bear and is apparently either a precursor or a product of chenodeoxycholate. Its administration changes the composition of bile and may dissolve gallstones. It is used as a cholagogue and choleretic.TokyoBile Duct Neoplasms: Tumors or cancer of the BILE DUCTS.Choledochostomy: Surgical formation of an opening (stoma) into the COMMON BILE DUCT for drainage or for direct communication with a site in the small intestine, primarily the DUODENUM or JEJUNUM.Portoenterostomy, Hepatic: Operation for biliary atresia by anastomosis of the bile ducts into the jejunum or duodenum.Bile Duct Diseases: Diseases in any part of the ductal system of the BILIARY TRACT from the smallest BILE CANALICULI to the largest COMMON BILE DUCT.Cholangiocarcinoma: A malignant tumor arising from the epithelium of the BILE DUCTS.Gallstones: Solid crystalline precipitates in the BILIARY TRACT, usually formed in the GALLBLADDER, resulting in the condition of CHOLELITHIASIS. Gallstones, derived from the BILE, consist mainly of calcium, cholesterol, or bilirubin.Sphincterotomy, Endoscopic: Incision of Oddi's sphincter or Vater's ampulla performed by inserting a sphincterotome through an endoscope (DUODENOSCOPE) often following retrograde cholangiography (CHOLANGIOPANCREATOGRAPHY, ENDOSCOPIC RETROGRADE). Endoscopic treatment by sphincterotomy is the preferred method of treatment for patients with retained or recurrent bile duct stones post-cholecystectomy, and for poor-surgical-risk patients that have the gallbladder still present.Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Cholangiopancreatography, Magnetic Resonance: Non-invasive diagnostic technique for visualizing the PANCREATIC DUCTS and BILE DUCTS without the use of injected CONTRAST MEDIA or x-ray. MRI scans provide excellent sensitivity for duct dilatation, biliary stricture, and intraductal abnormalities.Cholecystitis, Acute: Acute inflammation of the GALLBLADDER wall. It is characterized by the presence of ABDOMINAL PAIN; FEVER; and LEUKOCYTOSIS. Gallstone obstruction of the CYSTIC DUCT is present in approximately 90% of the cases.Common Bile Duct: The largest bile duct. It is formed by the junction of the CYSTIC DUCT and the COMMON HEPATIC DUCT.Hepatitis, Autoimmune: A chronic self-perpetuating hepatocellular INFLAMMATION of unknown cause, usually with HYPERGAMMAGLOBULINEMIA and serum AUTOANTIBODIES.Adenoma, Bile Duct: A benign tumor of the intrahepatic bile ducts.Liver Transplantation: The transference of a part of or an entire liver from one human or animal to another.Biliary Atresia: Progressive destruction or the absence of all or part of the extrahepatic BILE DUCTS, resulting in the complete obstruction of BILE flow. Usually, biliary atresia is found in infants and accounts for one third of the neonatal cholestatic JAUNDICE.Drainage: The removal of fluids or discharges from the body, such as from a wound, sore, or cavity.Common Bile Duct Diseases: Diseases of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Jaundice, Obstructive: Jaundice, the condition with yellowish staining of the skin and mucous membranes, that is due to impaired BILE flow in the BILIARY TRACT, such as INTRAHEPATIC CHOLESTASIS, or EXTRAHEPATIC CHOLESTASIS.Pancreatitis: INFLAMMATION of the PANCREAS. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of CHRONIC PANCREATITIS (International Symposium on Acute Pancreatitis, Atlanta, 1992). The two most common forms of acute pancreatitis are ALCOHOLIC PANCREATITIS and gallstone pancreatitis.Jejunostomy: Surgical formation of an opening through the ABDOMINAL WALL into the JEJUNUM, usually for enteral hyperalimentation.Colitis, Ulcerative: Inflammation of the COLON that is predominantly confined to the MUCOSA. Its major symptoms include DIARRHEA, rectal BLEEDING, the passage of MUCUS, and ABDOMINAL PAIN.Hepatic Duct, Common: Predominantly extrahepatic bile duct which is formed by the junction of the right and left hepatic ducts, which are predominantly intrahepatic, and, in turn, joins the cystic duct to form the common bile duct.Autoimmune Diseases: Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.Cholecystectomy: Surgical removal of the GALLBLADDER.Biliary Tract: The BILE DUCTS and the GALLBLADDER.Jaundice: A clinical manifestation of HYPERBILIRUBINEMIA, characterized by the yellowish staining of the SKIN; MUCOUS MEMBRANE; and SCLERA. Clinical jaundice usually is a sign of LIVER dysfunction.Caroli Disease: Congenital cystic dilatation of the intrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC). It consists of 2 types: simple Caroli disease is characterized by bile duct dilatation (ectasia) alone; and complex Caroli disease is characterized by bile duct dilatation with extensive hepatic fibrosis and portal hypertension (HYPERTENSION, PORTAL). Benign renal tubular ectasia is associated with both types of Caroli disease.Cholecystitis: Inflammation of the GALLBLADDER; generally caused by impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, or other diseases.Bile: An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.Choledocholithiasis: Presence or formation of GALLSTONES in the COMMON BILE DUCT.Sclerosis: A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve.Biliary Tract Surgical Procedures: Any surgical procedure performed on the biliary tract.Biliary Tract Neoplasms: Tumors or cancer in the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Liver Diseases: Pathological processes of the LIVER.Bile Ducts, Extrahepatic: Passages external to the liver for the conveyance of bile. These include the COMMON BILE DUCT and the common hepatic duct (HEPATIC DUCT, COMMON).Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).Acute Disease: Disease having a short and relatively severe course.Cholestasis, Extrahepatic: Impairment of bile flow in the large BILE DUCTS by mechanical obstruction or stricture due to benign or malignant processes.Lithiasis: A condition characterized by the formation of CALCULI and concretions in the hollow organs or ducts of the body. They occur most often in the gallbladder, kidney, and lower urinary tract.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Choledochal Cyst: A congenital anatomic malformation of a bile duct, including cystic dilatation of the extrahepatic bile duct or the large intrahepatic bile duct. Classification is based on the site and type of dilatation. Type I is most common.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Ampulla of Vater: A dilation of the duodenal papilla that is the opening of the juncture of the COMMON BILE DUCT and the MAIN PANCREATIC DUCT, also known as the hepatopancreatic ampulla.HLA-B8 Antigen: A specific HLA-B surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-B*08 allele family.Anastomosis, Roux-en-Y: A Y-shaped surgical anastomosis of any part of the digestive system which includes the small intestine as the eventual drainage site.HLA-DR Serological Subtypes: HLA-DR antigen subtypes that have been classified according to their affinity to specific ANTIBODIES. The DNA sequence analyses of HLA-DR ALPHA-CHAINS and HLA-DR BETA-CHAINS has for the most part revealed the specific alleles that are responsible for each serological subtype.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Endoscopy, Digestive System: Endoscopic examination, therapy or surgery of the digestive tract.Acalculous Cholecystitis: Inflammation of the GALLBLADDER wall in the absence of GALLSTONES.Inflammatory Bowel Diseases: Chronic, non-specific inflammation of the GASTROINTESTINAL TRACT. Etiology may be genetic or environmental. This term includes CROHN DISEASE and ULCERATIVE COLITIS.Recurrence: The return of a sign, symptom, or disease after a remission.Gallbladder: A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.Liver Function Tests: Blood tests that are used to evaluate how well a patient's liver is working and also to help diagnose liver conditions.Dilatation: The act of dilating.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Cholestasis, Intrahepatic: Impairment of bile flow due to injury to the HEPATOCYTES; BILE CANALICULI; or the intrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC).Hemobilia: Hemorrhage in or through the BILIARY TRACT due to trauma, inflammation, CHOLELITHIASIS, vascular disease, or neoplasms.Autoantibodies: Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.