Gallstones are very common, but at least two thirds of detected stones are asymptomatic and a large number undoubtedly go undetected. The presence of symptoms or complications is the indication for surgery. It is important to accurately identify which symptoms are caused by gallstones, because removing the gallbladder will relieve only these symptoms. Making this determination is a challenge, however, because the classic picture of biliary colic may be inaccurate and the connection between gallstone disease and flatulent dyspepsia is questionable at best. Descriptions of both these conditions are based on anecdotal evidence or reports of uncontrolled surgical series. A review of recent controlled trials suggests that the pain of biliary colic is constant and infrequent, comes in episodes lasting 1 to 5 hours, is located in the epigastrium or right upper quadrant of the abdomen, and characteristically occurs at night. There are few additional symptoms other than nausea or vomiting, and colic is not induced by eating fatty meals. Flatulent dyspepsia--a symptom complex of vague pain in the right upper quadrant, fatty-food intolerance, and bloating--is probably not related to the presence of gallstones in the majority of patients.