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.Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).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.Cholecystectomy: Surgical removal of the GALLBLADDER.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.Cholecystolithiasis: Presence or formation of GALLSTONES in the GALLBLADDER.Ileus: A condition caused by the lack of intestinal PERISTALSIS or INTESTINAL MOTILITY without any mechanical obstruction. This interference of the flow of INTESTINAL CONTENTS often leads to INTESTINAL OBSTRUCTION. Ileus may be classified into postoperative, inflammatory, metabolic, neurogenic, and drug-induced.Bile Pigments: Linear TETRAPYRROLES that give a characteristic color to BILE including: BILIRUBIN; BILIVERDIN; and bilicyanin.Cholecystectomy, Laparoscopic: Excision of the gallbladder through an abdominal incision using a laparoscope.Gallbladder Diseases: Diseases of the GALLBLADDER. They generally involve the impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, neoplasms, or other diseases.Gallbladder Emptying: A process whereby bile is delivered from the gallbladder into the duodenum. The emptying is caused by both contraction of the gallbladder and relaxation of the sphincter mechanism at the choledochal terminus.Cholecystography: Radiography of the gallbladder after ingestion of a contrast medium.Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.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.Bile Acids and Salts: Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Cholecystitis: Inflammation of the GALLBLADDER; generally caused by impairment of BILE flow, GALLSTONES in the BILIARY TRACT, infections, or other diseases.Chenodeoxycholic Acid: A bile acid, usually conjugated with either glycine or taurine. It acts as a detergent to solubilize fats for intestinal absorption and is reabsorbed by the small intestine. It is used as cholagogue, a choleretic laxative, and to prevent or dissolve gallstones.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 Fistula: Abnormal passage in any organ of the biliary tract or between biliary organs and other organs.Bilirubin: A bile pigment that is a degradation product of HEME.Gallbladder Neoplasms: Tumors or cancer of the gallbladder.Common Bile Duct: The largest bile duct. It is formed by the junction of the CYSTIC DUCT and the COMMON HEPATIC DUCT.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.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.Biliary Tract: The BILE DUCTS and the GALLBLADDER.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.Calcium Carbonate: Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Choledocholithiasis: Presence or formation of GALLSTONES in the COMMON BILE DUCT.Intestinal Fistula: An abnormal anatomical passage between the INTESTINE, and another segment of the intestine or other organs. External intestinal fistula is connected to the SKIN (enterocutaneous fistula). Internal intestinal fistula can be connected to a number of organs, such as STOMACH (gastrocolic fistula), the BILIARY TRACT (cholecystoduodenal fistula), or the URINARY BLADDER of the URINARY TRACT (colovesical fistula). Risk factors include inflammatory processes, cancer, radiation treatment, and surgical misadventures (MEDICAL ERRORS).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).Cholic Acids: The 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholanic acid family of bile acids in man, usually conjugated with glycine or taurine. They act as detergents to solubilize fats for intestinal absorption, are reabsorbed by the small intestine, and are used as cholagogues and choleretics.Biliary Tract Neoplasms: Tumors or cancer in the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Abdominal Abscess: An abscess located in the abdominal cavity, i.e., the cavity between the diaphragm above and the pelvis below. (From Dorland, 27th ed)Lithotripsy: The destruction of a calculus of the kidney, ureter, bladder, or gallbladder by physical forces, including crushing with a lithotriptor through a catheter. Focused percutaneous ultrasound and focused hydraulic shock waves may be used without surgery. Lithotripsy does not include the dissolving of stones by acids or litholysis. Lithotripsy by laser is LITHOTRIPSY, LASER.Dysbiosis: Changes in quantitative and qualitative composition of MICROBIOTA. The changes may lead to altered host microbial interaction or homeostatic imbalance that can contribute to a disease state often with inflammation.Cholesterol, Dietary: Cholesterol present in food, especially in animal products.Subphrenic Abscess: Accumulation of purulent EXUDATES beneath the DIAPHRAGM, also known as upper abdominal abscess. It is usually associated with PERITONITIS or postoperative infections.Lithocholic Acid: A bile acid formed from chenodeoxycholate by bacterial action, usually conjugated with glycine or taurine. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as cholagogue and choleretic.Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Sciuridae: A family of the order Rodentia which contains 49 genera. Some of the more common genera are MARMOTA, which includes the marmot and woodchuck; Sciurus, the gray squirrel, S. carolinensis, and the fox squirrel, S. niger; Tamias, the eastern and western chipmunk; and Tamiasciurus, the red squirrel. The flying squirrels, except the scaly-tailed Anomaluridae, also belong to this family.Cholangitis: Inflammation of the biliary ductal system (BILE DUCTS); intrahepatic, extrahepatic, or both.Sigmoid Diseases: Pathological processes in the SIGMOID COLON region of the large intestine (INTESTINE, LARGE).Ileal Diseases: Pathological development in the ILEUM including the ILEOCECAL VALVE.Cholic Acid: A major primary bile acid produced in the liver and usually conjugated with glycine or taurine. It facilitates fat absorption and cholesterol excretion.Cholesterol 7-alpha-Hydroxylase: A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.Duodenal Obstruction: Hindrance of the passage of luminal contents in the DUODENUM. Duodenal obstruction can be partial or complete, and caused by intrinsic or extrinsic factors. Simple obstruction is associated with diminished or stopped flow of luminal contents. Strangulating obstruction is associated with impaired blood flow to the duodenum in addition to obstructed flow of luminal contents.Crystallization: The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Lecithins: A complex mixture of PHOSPHOLIPIDS; GLYCOLIPIDS; and TRIGLYCERIDES; with substantial amounts of PHOSPHATIDYLCHOLINES; PHOSPHATIDYLETHANOLAMINES; and PHOSPHATIDYLINOSITOLS, which are sometimes loosely termed as 1,2-diacyl-3-phosphocholines. Lecithin is a component of the CELL MEMBRANE and commercially extracted from SOYBEANS and EGG YOLK. The emulsifying and surfactant properties are useful in FOOD ADDITIVES and for forming organogels (GELS).Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Gilbert Disease: A benign familial disorder, transmitted as an autosomal dominant trait. It is characterized by low-grade chronic hyperbilirubinemia with considerable daily fluctuations of the bilirubin level.Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Gastric Outlet Obstruction: The hindering of output from the STOMACH into the SMALL INTESTINE. This obstruction may be of mechanical or functional origin such as EDEMA from PEPTIC ULCER; NEOPLASMS; FOREIGN BODIES; or AGING.Polyps: Discrete abnormal tissue masses that protrude into the lumen of the DIGESTIVE TRACT or the RESPIRATORY TRACT. Polyps can be spheroidal, hemispheroidal, or irregular mound-shaped structures attached to the MUCOUS MEMBRANE of the lumen wall either by a stalk, pedunculus, or by a broad base.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Receptor, Cholecystokinin A: A subtype of cholecystokinin receptor found primarily in the PANCREAS; STOMACH; INTESTINE; and GALLBLADDER. It plays a role in regulating digestive functions such as gallbladder contraction, pancreatic enzyme secretion and absorption in the GASTROINTESTINAL TRACT.Jejunal Diseases: Pathological development in the JEJUNUM region of the SMALL INTESTINE.Duodenal Diseases: Pathological conditions in the DUODENUM region of the small intestine (INTESTINE, SMALL).Pigments, Biological: Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.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.Cystic Duct: The duct that is connected to the GALLBLADDER and allows the emptying of bile into the COMMON BILE DUCT.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Hydroxymethylglutaryl CoA Reductases: Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.Common Bile Duct Diseases: Diseases of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Acute Disease: Disease having a short and relatively severe course.