Cholelithiasis in inflammatory bowel disease. A case-control study.

Cholelithiasis is considered an extraintestinal manifestation of Crohn's ileitis but has not been associated with ulcerative colitis. To evaluate if an increased risk of cholelithiasis exists in patients with ulcerative colitis, biliary ultrasonography was performed on 159 patients with inflammatory bowel disease, 114 patients with ulcerative colitis, and 45 patients with Crohn's disease. A control population of 2453 residents of the town near the authors' institute was also studied. An echographic survey of gallstones was performed on the control subjects, who participated in the Multicentrica Italiana Colelitiasi (MICOL). Seventeen patients with inflammatory bowel disease had gallstones (10.7 percent), 11 patients with ulcerative colitis had gallstones (9.6 percent), and 6 patients with Crohn's disease had gallstones (13.3 percent). In the control population, diagnosis of cholelithiasis was made in 239 subjects (9.7 percent). An estimate of the relative risk (odds ratio) of gallstones in ulcerative colitis and Crohn's disease and also in 4 subgroups formed on the basis of the extent of disease (total ulcerative colitis, partial ulcerative colitis, Crohn's disease with ileitis, Crohn's disease without ileitis) with respect to the general population was calculated using logistic regression with gallstones, sex, age, and body mass index as independent variables and inflammatory bowel disease as a dependent variable. The author's findings show an increased risk of gallstones in both patients with Crohn's disease (odds ratio = 3.6; 95 percent confidence limits = 1.2 - 10.4; P = 0.02) and patients with ulcerative colitis (odds ratio = 2.5; 95 percent confidence limits = 1.2 - 5.2; P = 0.01). The risk was highest in patients with Crohn's disease involving the distal ileum (odds ratio = 4.5; 95 percent confidence limits = 1.5 - 14.1; P = 0.009) and in patients with total ulcerative colitis extending to the cecum (odds ratio = 3.3; 95 percent confidence limits = 1.3 - 8.6; P = 0.01). These results confirm that there is an increased risk of gallstones in Crohn's ileitis but they show that there also exists an increased risk in patients with total ulcerative colitis.