Darrell Williams, age 12, of Louisville, Ky., for his question:
WHAT ARE GALLSTONES?
Gallstones are hard objects like little pebbles or stones that form in the gall bladder or bile duct. The stones are largely made of cholesterol, a kind of alcohol found in animal fats, bile, blood, liver and other tissues.
In some diseases of the gall bladder or liver, cholesterol together with bile pigments, mineral salts and other body products hardens into these stones.
Doctors tell us that close to one third of all women and one sixth of all men over the age of 40 have gallstones in some form. Sometimes they cause no pain or discomfort and are detected only during an X ray examination for another problem.
Doctors also believe that gallstones are more likely to occur in persons who eat the kind of high fat and high cholesterol diet that is very common today.
When a gall bladder contracts, a stone may become caught in one of its ducts and cause great pain. A small stone may pass from the gall bladder to the common bile duct and cause pain or fever. The flow of bile into the duodenum may be cut off, causing a yellowing of the skin and body tissues called jaundice.
Sometimes a surgical operation is necessary to remove gallstones.
When a gallstone is lodged in the gall bladder, the disorder is known as cholelithiasis. If they block the passage from the gall bladder, or lodge in the ducts that normally carry bile to the intestines, the problem is call choledocholithiasis.
Gallstones actually may lodge in a number of locations, such as a liver duct, blocking the flow of bile from the liver and causing complications in that organ, or in the common duct, obstructing flow not only of bile but also of pancreatic juices.
Cholesterol is a fatlike substance that is formed in the liver and much of it is converted into bile salts. But some cholesterol does not change chemically and can cause trouble.
If too much cholesterol gets into the bile, or if there is too little of some unknown factor that helps keep cholesterol in solution, cholesterol settles in solid particles that aggregate into gallstones.
Sometimes gallstones are small, numerous and sandlike. But as the conditions for precipitation of cholesterol continue, they may harden and consolidate. The result may be the formation of a huge stone which nearly fills the gall bladder.
When a doctor operates to remove gallstones, often the entire gall bladderis removed to prevent the formation of further stones. This body part is not essential to the digestive process. Bile can flow directly from the liver to the duodenum without storage.
One of the risks of gallstones is infection. Bacteria find the blocked or sluggish bile passage a fertile place to multiply.