  What Is the Gallbladder?  The gallbladder is a four-inch,
olive-shaped muscular sac that lies under the liver in the right
side of the abdomen. It acts as a reservoir for bile, a fluid
made in the liver. Bile is important for the digestion of fat
and also carries some waste products out of the body. The
gallbladder is connected to the liver and small intestine
through a system of small channels called ducts. When food
enters the small intestine, a hormone called cholecystokinin is
released, signaling the gallbladder to contract and release
bile. The bile flows through the common bile duct into the small
intestine. Bile breaks down (emulsifies) fat so that it can be
absorbed along with fat-soluble nutrients such as vitamins A, D,
E, and K into the bloodstream. Bile is composed of water, bile
salts, lecithin (a fat known as a phospholipid), and
cholesterol.  Gallstones can develop  Gallstones are small, hard
pellets that form in the gallbladder when the concentration of
cholesterol or bilirubin in the bile be