Mechanisms of Disease: nicotine—a review of its actions in the context of gastrointestinal disease

Smoking can have a detrimental and beneficial effect on gastrointestinal disease—it has such a 'polarizing effect' in patients with Crohn's disease and ulcerative colitis. Studies in tobacco smokers have made it difficult to identify which agents are responsible for these effects, but work on the action of nicotine alone might help to explain some of the positive and negative links between smoking and gastrointestinal disease.