Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Biliary Tract Neoplasms: Tumors or cancer in the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Biliary Tract: The BILE DUCTS and the GALLBLADDER.Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).Cholecystitis: Inflammation of the GALLBLADDER; generally caused by impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, or other diseases.Cholecystectomy: Surgical removal of the GALLBLADDER.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.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.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.Cholestasis, Extrahepatic: Impairment of bile flow in the large BILE DUCTS by mechanical obstruction or stricture due to benign or malignant processes.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).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.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.Biliary Tract Surgical Procedures: Any surgical procedure performed on the biliary tract.Respiratory Tract DiseasesLiver Diseases: Pathological processes of the LIVER.Gallbladder Neoplasms: Tumors or cancer of the gallbladder.Acute Disease: Disease having a short and relatively severe course.Urologic Diseases: Pathological processes of the URINARY TRACT in both males and females.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Cholangiocarcinoma: A malignant tumor arising from the epithelium of the BILE DUCTS.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).Bile Duct Neoplasms: Tumors or cancer of the BILE DUCTS.Respiratory Syncytial Virus Infections: Pneumovirus infections caused by the RESPIRATORY SYNCYTIAL VIRUSES. Humans and cattle are most affected but infections in goats and sheep have been reported.Digestive System Diseases: Diseases in any part of the GASTROINTESTINAL TRACT or the accessory organs (LIVER; BILIARY TRACT; PANCREAS).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.Cholangitis: Inflammation of the biliary ductal system (BILE DUCTS); intrahepatic, extrahepatic, or both.Respiratory Syncytial Virus, Human: The type species of PNEUMOVIRUS and an important cause of lower respiratory disease in infants and young children. It frequently presents with bronchitis and bronchopneumonia and is further characterized by fever, cough, dyspnea, wheezing, and pallor.Respiratory Syncytial Viruses: A group of viruses in the PNEUMOVIRUS genus causing respiratory infections in various mammals. Humans and cattle are most affected but infections in goats and sheep have also been reported.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.Bocavirus: A genus in the subfamily PARVOVIRINAE comprising three species: Bovine parvovirus, Canine minute virus, and HUMAN BOCAVIRUS.Pancreatic Diseases: Pathological processes of the PANCREAS.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.Metapneumovirus: A genus of the subfamily PNEUMOVIRINAE, containing two members: Turkey rhinotracheitis virus and a human Metapneumovirus. Virions lack HEMAGGLUTININ and NEURAMINIDASE.Urinary Tract: The duct which coveys URINE from the pelvis of the KIDNEY through the URETERS, BLADDER, and URETHRA.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.Common Bile Duct: The largest bile duct. It is formed by the junction of the CYSTIC DUCT and the COMMON HEPATIC DUCT.Gastrointestinal Diseases: Diseases in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.