How does smoking affect Ulcerative Colitis?

Research studies have shown that UC is less common in smokers than nonsmokers. Some people have developed UC once they have given up smoking.

This suggests that smoking may delay or prevent UC, as well as reducing its severity. There are also studies that show that smokers with UC appear to suffer a milder form of the condition. Flare-ups, hospitalization rates, the need for oral steroids or immunosuppressants, and colectomy rates are all reported to be lower in patients who smoke.

However, not all studies agree with this. For example, one study found that people with UC who smoked had an increased risk of developing joint and skin problems.

In general, health professionals consider the risks of smoking heavily outweigh any benefits seen in UC, and strongly discourage smoking in everyone, whether or not they have IBD. 


Again, we do not really know why smoking has a protective effect against UC. It is thought that of the many chemicals in tobacco, nicotine is the most likely to have an impact.

It has been found that people who have UC may have a thinner mucus layer in the left colon and rectum when compared to healthy people. It is possible that nicotine may increase the production of this mucus. Nicotine may also suppress the immune system and prevent inflammation in the colon. Another theory is that nitric oxide, released by nicotine, may reduce muscle activity in the colon and so reduce the need to go the toilet urgently.


It may be tempting to continue or even take up smoking to help your UC. However, not all research on smoking and IBD has come to a similar conclusion. Also, smoking increases your risk of chronic bronchitis, lung cancer, other cancers and heart diseases, and is not recommended by health professionals even for people with UC. There are many treatments much safer than smoking which could be explored.

As yet, there has been no research into the effect of using electronic cigarettes on Ulcerative Colitis. In addition, electronic cigarettes are not currently regulated, so you cannot be sure how much nicotine is in them, and whether there are any other ingredients. There is also no clear evidence to show that they are safe.


There have been a number of studies on the effects of nicotine patches or chewing nicotine gum in treating UC. For mild or moderately active UC, it appears that nicotine patches or gum can sometimes help.

However, not everybody can tolerate nicotine. In several studies, people who tried nicotine treatment for IBD suffered side effects such as dermatitis, nausea, headaches or sleep disturbance. Although nicotine appeared to help with active disease, it did not seem to be as beneficial when given as maintenance therapy (taking it continuously) to prevent flare-ups. Research has also indicated that nicotine is less effective than several more conventional IBD drug treatments, such as 5-ASAs and steroids.