It is estimated that over 20 million Americans have cholelithiasis (stones in the gallbladder) and that almost one million new cases are diagnosed each year. Nearly 600,000 cholecystectomies are performed annually, ranking this surgical procedure among the five most frequently performed in the United States(1). Gallstones are common in people over 40 years of age, but they can also occur in teenagers. Women are affected four times more frequently than men are, and it has also been estimated that gallstones remain undetected in 60 to 80 percent of the population(2). Gallstones are prevalent in people in the United States, Western European countries, and Australia; they are rarely found in the people of Africa, particularly in the sub-Sahara region. In one study, gallstones in Americans were composed of cholesterol 92 percent of the time. In Orientals, however, the cholesterol content of stones was minimal, and stones were more likely to contain a high percent of bilirubin pigments(3). Gallstones are the most common cause of gallbladder disease (cholecystitis), but stones may also be present in such rare diseases as cholesterolosis (abnormal amounts of cholesterol in the tissues), adenomyoma, or carcinoma of the gallbladder. Several diseases and clinical states are associated with a high incidence of gallstones. Hemolytic disorders and cholesterol saturation of the bile both predispose an individual to biliary stones. Patients who have had extensive bowel resection for Crohn's disease have a three-to-fivefold increase in gallstones, possibly due to the interruption of recirculation of bile salts. Obesity and diabetes mellitus increase the likelihood of gallstones. Oral contraceptives and multiple pregnancies also increase the chance of stones. Oral contraceptives appear to alter the bile, which results in increasingly greater cholesterol saturation(4).