Why do gallstones cause jaundice?

Blockage of bile. They can block bile from exiting the liver. This prevents the liver from getting rid of bilirubin, which is bright yellow in color, and builds up in th eblood and stains skin and eye sclerae - this is what's known as jaundice.
CBD Stone. On occasion, gallstones can exit the gallbladder and enter the tube that connects the liver to the intestine, called the common bile duct (cbd). This can block the outflow of bile from the liver; the bile pigments that are normally excreted in the intestine end up in the bloodstream, causing jaundice. This is a serious problem that warrants urgent medical attention.