Smoking and IBD

The effect of smoking on IBD differs depending on whether you have Crohn’s disease or ulcerative colitis.


Crohn’s disease

Smoking as a significant detrimental effect in Crohn’s disease, specifically:

  • Smokers are at a greater risk of developing Crohn’s disease
  • Non-smoking Crohn’s disease patients spend less time experiencing disease activity (i.e., inflammation) than those that smoke
  • Smoking is a risk factor for more developing more serious Crohn’s disease symptoms (e.g., structuring, fistulas)
  • Smokers are more likely to need surgery compared to non-smokers
  • Those that quit smoking are at a lesser risk of flare ups, and less likely to need steroids or immunosuppressant drugs


Ulcerative colitis

Research has found smoking to be a protective factor for ulcerative colitis. Specifically:

  • Smokers are less likely to develop ulcerative colitis
  • Smokers experience a less severe illness course (i.e., less inflammation, less likelihood of colectomy surgery)
  • Cessation of smoking is associated with an increase in ulcerative colitis symptoms


Although smoking has some beneficial effects for ulcerative colitis, the exact nature of its protective influence and how it works is not well understood. Furthermore, the potential benefits of smoking need to be viewed in the context of its’ significant dangers. The decision to smoke comes with serious risks such as cardiovascular disease and is known to cause thirteen different types of cancers.Smoking can also reduce the effectiveness of some IBDmedications. Given the significant adverse impact of smoking on health (including mortality) it is not recommended, for information about quitting smoking head to