What are gallstones?

What are gallstones?

Gallstones begin with bile, a substance that helps with the digestion of fats and the absorption of certain vitamins. Bile is made in the liver and carried to the gallbladder, a small, pear-shaped organ that concentrates and stores it. The fat in food triggers the release of a hormone that causes the gallbladder to contract and release bile into the intestine.

Gallstones are solid lumps that develop when the stored bile crystallizes. Most are less than an inch in diameter, but they can be as small as a grain of sand or as large as a golf ball. Most gallstones are composed mainly of cholesterol. The rest known as pigment stones  are made of calcium salts and bilirubin, a breakdown product of red blood cells.

Cholesterol stones form when liquid bile in the gallbladder contains more cholesterol than the bile salts can dissolve. Cholesterol stones may also develop if the gallbladder doesn't contract and empty as it should. Pigment stones are associated with certain medical conditions, including liver disease, some types of anemia, and infection of the bile ducts