Gallbladder disease, bile composition and bile acid absorption after partial ileal bypass.

The incidence of gallbladder disease (gallstones or cholecystectomy) in 24 ileal bypass patients and in 24 unoperated matched controls, all heterozygous for familial hypercholesterolemia, was studied during a follow-up period of nine years on average. Gallbladder disease developed in 6 patients with ileal bypass and in one control patient (p less than 0.05). The operated patients who developed gallbladder disease were slightly older and had a higher serum cholesterol concentration at the start than those who did not, but otherwise the development of gallbladder disease could not be predicted by serum lipids or serial measurement of bile acid and cholesterol synthesis. At the end of the follow-up, the unoperated subjects had gained in weight. Moreover, the biliary lipid composition and the cholesterol saturation index of the bile were similar in the operated (n = 10) and unoperated (n = 10) patients studied. Indirect measurements suggested that the bile acid secretion was not changed by the operation, although the fractional bile acid absorption was significantly lowered in the operated subjects, especially in three subjects taking cholestyramine. All these three subjects had supersaturated bile. It is concluded that ileal bypass carries an increased risk of gallbladder disease although the cholesterol saturation index of the bile shows no significant difference between the operated and the control patients when studied years after the operation, when the control patients have gained in weight.