The fecal bile acid excretion pattern was investigated in 25 cholecystectomized and 26 noncholecystectomized patients as a measure for the exposure of the colonic mucosa to bile acids. Separation of free, conjugated, and sulfated bile acids was achieved by liquid-gel chromatography using DEAP Sephadex LH-20 and quantification of individual bile acids by gas-liquid chromatography. Total bile acid concentration was higher in cholecystectomized (5.33 +/- 0.71 mg/g) than in noncholecystectomized patients (3.69 +/- 0.65 mg/g). Deoxycholic acid excretion was elevated in cholecystectomized patients in three aspects: the concentration of deoxycholic acid was higher (2.92 +/- 0.39 mg/g and 1.71 +/- 0.35 mg/g, respectively), its percentage proportion of total bile acids was increased (53.9 +/- 2.8% and 41.4 +/- 3.1%, respectively), and its daily output was twice as large as that in patients without previous cholecystectomy (63.2 +/- 11.5 and 32.9 +/- 5.9 mg/day, respectively).