SURGICAL AND SMOKING HISTORY IN INFLAMMATORY BOWEL-DISEASE - A CASE-CONTROL STUDY

An inverse relation between appendectomy and ulcerative colitis and sm oking and ulcerative colitis has been proposed. Our study examined the frequency of common surgical interventions and of smoking in 500 pati ents with inflammatory bowel disease. They comprised 177 patients with ulcerative colitis, 134 patients with Crohn's disease, and 189 contro ls matched for age, sex, and socioeconomic group. Subjects were questi oned on all previous surgery and on smoking history. The appendectomy rate among controls was 17.5% (33 of 189), which was significantly gre ater than that of patients with ulcerative colitis: 8.5% (15 of 177; p < 0.05). However, after using multiple variable logistic regression a nalysis, this was no longer statistically significant. There was no si gnificant difference in appendectomy rate between patients with Crohn' s disease and controls. The three groups had comparable rates of tonsi llectomy and cholecystectomy. Of patients with ulcerative colitis, 84. 2% were nonsmokers at the time of diagnosis in contrast to 50.4% among the patients with Crohn's disease (p < 0.01). In this case-control st udy, by using multivariate logistic regression analysis, appendectomy offers no significant protection from developing ulcerative colitis or Crohn's disease. Smoking appears to be deleterious in Crohn's disease , whereas a cessation of smoking precedes the onset of ulcerative coli tis in a significant number of cases.