Effect of cigarette smoking on recurrence of Crohn's disease.

The effect of cigarette smoking on recurrence (defined in this study as the need for repeat surgery) in patients who had previously required surgery for Crohn's disease was assessed in a historical cohort of 174 patients. Mean follow-up was 10.8 yr. The 5- and 10-yr recurrence rates were 28% and 56%, respectively. Five- and 10-yr rates were significantly different for smokers (36%, 70%) and nonsmokers (20%, 41%). When patients were stratified by gender, the increased risk was more apparent in women (odds ratio 4.2, 95% confidence interval 2.0-4.2) than in men (odds ratio 1.5, 95% confidence interval 0.8-6.0). Evidence for a dose-response relationship could be identified in women but not men. Cigarette smoking may not only be a risk factor for development of Crohn's disease but also may influence disease activity following surgery.