Smoking, smoking cessation and Crohn's disease

Context > Smoking whose prevalence is higher in patients with Crohn's disease (CD) worsens its evolution. Ulcerative colitis mostly affect non-or ex-smokers; smoking may improve the course of the disease. Objectives > Systematic literature review of data on the relationship between smoking, smoking cessation and Crohn'disease. Documentary sources > Medline, on the period 1980-2015 with the keywords "Crohn's disease'' or "inflammatory bowel disease'' and "smoking'' or "smoking cessation''; limits "Title/Abstract''; the selected languages were English or French. Study selection > Among 1315 articles, 168 abstracts have given rise to a dual reading to select 69 studies (case-control, retrospective, reviews or meta-analysis). Data were extracted using a reading gate. Results > Smoking increases the risk of complications, recurrences and resort of surgery, corticosteroids or immunosuppressants. These deleterious effects are more common in women. Stopping smoking improves the course of the disease and represents an essential component of its management. Limits > Heterogeneity of the studies collected according to the type, population characteristics, definition of smoking status and the validation of smoking cessation. Conclusion > Smokers suffering from CD must routinely be made aware of the disadvantages of smoking, benefits of abstinence and helped to quit smoking.