Gallstones form in the gallbladder, a small organ under the liver, from an excess of cholesterol and bilirubin in the digestive fluid (bile) that is stored there. Gallstones can be “silent” – meaning no pain and usually no treatment, or cause pain and other symptoms as they enter the ducts to the small intestine. Increased risk for gallstones is associated with obesity, diabetes and a diet high in cholesterol or fat. Gallstones are treated with surgery and medication, depending on the severity.