The gall bladder is a small bag, roughly the shape and size of a pear that sits underneath the liver, on the right side of the abdomen. Its main purpose is to store and concentrate bile produced by the liver. Bile is released from the gallbladder after eating, aiding digestion. Bile travels through common bile ducts (CBD) into the small intestine. Gallstones are pieces of solid material that form in the gallbladder. These stones develop because cholesterol and pigments in bile sometimes form hard particles.