Copyright ©2007 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 14, 2007; 13(46): 6134-6139
Published online Dec 14, 2007. doi: 10.3748/wjg.v13.i46.6134
Smoking in inflammatory bowel diseases: Good, bad or ugly?
Peter Laszlo Lakatos, Tamas Szamosi, Laszlo Lakatos
Peter Laszlo Lakatos, Tamas Szamosi, 1st Department of Medicine, Semmelweis University, Budapest, Hungary
Laszlo Lakatos, 1st Department of Medicine, Csolnoky F. County Hospital, Veszprem, Hungary
Author contributions: All authors contributed equally to the work.
Correspondence to: Peter Laszlo Lakatos, MD, PhD, 1st Department of Medicine, Semmelweis University, Koranyi str. 2/A, H-1083, Hungary. kislakpet@bel1.sote.hu
Telephone: +36-1-2100278-1500 Fax: +36-1-3130250
Received: August 27, 2007
Revised: September 20, 2007
Accepted: October 26, 2007
Published online: December 14, 2007

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn’s disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing Crohn’s disease and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves Crohn’s disease. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

Keywords: Smoking, Crohn's disease, Ulcerative colitis, Phenotype