liver and gallbladder disorders
Gallstones
Introduction
Gallstones are collections of solid material (predominantly crystals of cholesterol) in the gallbladder. The liver can secrete too much cholesterol, which is carried with bile to the gallbladder, where the excess cholesterol forms solid particles and accumulates. Gallstones sometimes cause upper abdominal pain that can last for hours. Ultrasonography is quite accurate in detecting gallstones. If gallstones cause recurrent pain or other problems, the gallbladder is removed. The gallbladder is a small, pear-shaped sac located beneath the liver. It stores bile, a fluid that is produced by the liver and aids in digestion. When bile is needed, as when people eat, the gallbladder contracts, pushing bile through the bile ducts into the small intestine. (See also Overview of Gallbladder and Bile Duct Disorders and figure Most disorders of the gallbladder and bile ducts result from gallstones. The risk factors for gallstones include the following: Female sex Older age American Indian ethnicity Obesity Rapid weight loss (as results from a very low calorie diet or weight-loss surgery) A typical Western diet A family history of gallstones In the United States, over 15% people age 60 to 75 have gallstones. Stones in the gallbladder (also called cholelithiasis) sometimes pass into the bile ducts, or stones may form in the bile ducts. Stones in the bile ducts are called choledocholithiasis. These stones sometimes block a bile duct. Most gallstones do not cause symptoms. But if symptoms or other problems occur, treatment is necessary. Each year, more than half a million people in the United States have their gallbladder surgically removed. Gallstones are usually composed of cholesterol that has crystallized from bile. They form in the gallbladder. They may leave the gallbladder and lodge in the cystic duct, the common bile duct, or the ampulla of Vater. In the Western world, the major component of most gallstones is cholesterol, a fat (lipid) that normally is dissolved in bile (but not in water). When the liver secretes excess cholesterol, bile becomes oversaturated with cholesterol. The excess forms solid particles (cholesterol crystals). These microscopic crystals accumulate in the gallbladder, where they clump and grow into gallstones. Other types of gallstones form in the same way, but the solid particles are calcium compounds or bilirubin (the main pigment in bile). Stones composed of bilirubin, called pigment stones, are either black (forming in the gallbladder) or brown (forming in the bile ducts). Black pigment stones are more likely to develop in people who have Alcohol-Related Liver Disease and/or cirrhosis, who are older, or who have The stones may stay in the gallbladder or pass into bile ducts. Stones can block the cystic duct, common bile duct, or ampulla of Vater (where the common bile duct and pancreatic duct join). Most cholesterol stones in the bile ducts come from the gallbladder. Any narrowing (stricture) of the bile ducts can lead to a blockage or slow bile flow. Bacterial infections can develop when bile flow is slowed or blocked. Sometimes microscopic particles of cholesterol, calcium compounds, bilirubin, and other materials accumulate but do not form stones. This material is called biliary sludge. Sludge develops when bile remains in the gallbladder too long, as it does during pregnancy. Gallbladder sludge usually disappears when its cause resolves, for example, when pregnancy ends. However, sludge can evolve into gallstones or pass into the biliary tract and block the ducts. Fatty foods are no more likely to trigger pain due to gallstones than other foods. 