Smoking and Crohn’s Disease

Many studies have shown that there is an association between smoking and the development of Crohn’s disease (CD) and that it is an independent risk factor for the clinical, endoscopic and surgical recurrence of the disease.

It has been shown that there is a significant increase of recurrence and severity of the disease in all these areas related to the number of cigarettes smoked and the length of time a person has been smoking. Ex-smokers run a similar risk of recurrence to non-smokers with the disease. Smokers are more likely to have to undergo surgery, and have more rapid return of disease following their operations.

The reason for the adverse effects of smoking on Crohn’s Disease is still poorly understood.

Smoking appears to play a significant part in creating a predisposition for the recurrence of the disease due to several possible factors:

  1. The intestinal blood supply contains an early element in the pathogenesis of Crohn’s Disease – granulomas, which are the hallmark of CD, are often found within the walls of blood vessels and are a marker of inflammation. Smoking may cause a vasculitis which some workers have associated with the development of CD.
  2. It may alter the composition of mucus in the gut and therefore the protective barrier of the intestinal wall.
  3. It may influence the immune response which has also been found to play a part in the pathogenesis of Crohn’s Disease.

If you have Crohn’s Disease it is folly to smoke! This includes recreational drugs as well as tobacco!

Remember that smoking also has other unpleasant effects. It reduces general fitness and it can cause cancer, heart disease and chronic bronchitis. It causes premature ageing of the skin, especially in women. provides general information only and should not be regarded as a substitute for medical advice from your own doctor or healthcare provider.
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