Rapid cholesterol nucleation time and cholesterol gall stone formation after subtotal or total colectomy in humans.

Changes in biliary lipid composition, pH, ionised calcium, total and unconjugated bilirubin, and cholesterol nucleation time of gall bladder bile samples were examined in six patients who had undergone subtotal or total colectomy between five months and seven years previously, and values were compared with those in control patients with no gall stones. The colectomy group mainly comprised patients with ulcerative colitis and familial adenomatosis coli, in whom only a short length of the terminal ileum (mean (SEM) 2.25 (0.57) cm) had been resected. The reconstruction procedures were ileoanal anastomosis in two patients, terminal ileostomy in two, ileorectal anastomosis in one, and J shaped ileal pouch-anal anastomosis in one patient. The distributions of age, sex, and relative body weight were similar in the two groups. The gall bladder bile was lithogenic in the post colectomy group--these patients had a significantly increased cholesterol saturation index (p < 0.01) and rapid cholesterol nucleation time (p < 0.05) compared with the control group. A significant increase in the molar percentage of cholesterol and a decrease in that of total bile acid associated with significantly decreased secondary bile acids (p < 0.05) were observed in the post colectomy group. Gall stones formed in two of six patients after colectomy were cholesterol stones containing more than 80% cholesterol by dry weight. Total and unconjugated bilirubin, pH, and ionised calcium values were similar in the two groups. The results indicate that after total or subtotal colectomy the composition of gall bladder bile increases the risk of cholesterol gall stone formation.