Gallstones are made from the accumulation of liquid bile in the gallbladder that form into hardened stones. There are two types of stones that can form, ones that are made from cholesterol and ones that are made from bilirubin. Both of these substances are components of the bile itself, and bilirubin is a waste product. When the bile in the gallbladder is high in cholesterol and/or bilirubin, it is then that gallstones form. They can take on the form of one large mass, or many smaller ones. Not all gallstones cause inflammation as they often will break back up on their own. When they don't, but instead get stuck in any of the ducts that bile flows in and out of, inflammation, and complications resulting from inflammation, occur. It can be quite painful, and in some cases require surgical removal of the gallbladder.