Final answer:
Gallstones are primarily made up of cholesterol. When they block the bile duct, they can cause jaundice and pain by preventing bile excretion and leading to bilirubin accumulation.
Step-by-step explanation:
Gallstones are solid precipitates that form in the gallbladder. They are primarily composed of cholesterol, along with small amounts of calcium salts, glycerophospholipids, and fatty acids. Normally, excess cholesterol is secreted into the intestine as a component of bile. However, when cholesterol precipitates and forms gallstones, it can lead to health issues.
If a gallstone blocks the bile duct, bile cannot be excreted, which leads to the accumulation of the bile pigment bilirubin in the liver and bloodstream, causing jaundice. Jaundice is characterized by yellowing of the skin and the whites of the eyes. Moreover, large gallstones that obstruct the bile duct can cause significant pain and require medical attention.