Side effects include pain from catheterization and occasionally anesthetization from the ether. Extracorporeal shock-wave lithotripsy, the treatment of choice for kidney stones, has also proved to be effective for noncalcified gallstones. As with the other treatments, not all patients are suitable candidates. The typical gallstone patient has been described as fat, forty, fertile, fecund, and female with a family history of gallstones. Of these risk factors, only weight can be modified, at least theoretically.
Obesity is a well-studied risk factor for gallstone formation.
Compared with normal- weight individuals, obese people synthesize more cholesterol, secrete more cholesterol into the bile, and may be less efficient at gallbladder emptying. However, it should be noted that a substantial number of gallstone patients are not overweight. Measurement was done directly when possible, or calculated from records of three defecations. By contrast, a separate study of overweight women with gallstones showed no tendency for slow intestinal transit, although the women did have other risk factors. The investigators suggested that slow intestinal transit could enhance the formation and absorption of deoxycholate from the colon.