Should patients with inflammatory bowel disease smoke?

Should patients with inflammatory bowel disease smoke?An observation that fewer people with ulcerative colitis smoked cigarettes than would be expected' has been confirmed by further studies.2-4The relevance of this finding is at present not clear,5 but it has been suggested that smoking may protect against ulcerative colitis.The reports received widespread publicity, and we are often asked by patients with the disease for advice on smoking.We therefore studied smoking habits in patients with inflammatory bowel disease to ascertain whether smoking is associated with less severe disease. Patients, methods, and resultsA total of 252 consecutive outpatients with inflammatory bowel disease were interviewed and their case notes reviewed.Details were obtained of smoking habit, frequency of relapse, symptoms in remission and relapse, extent of disease, complications, and the numbers of admissions to hospital ana of operations.The means of the three most recent full blood cell counts, white cell counts, erythrocyte sedimentation rates, albumin concentrations, and platelet counts were recorded.Patients were subdivided into three groups on conventional clinical grounds: 102 patients had ulcerative colitis, 96 Crohn's colitis, and 54 Crohn's disease of the small bowel.Patients with Crohn's disease in both the small bowel and the colon were included in the third group.Analysis of 172 variables for each patient was carried out with an ICL 2970 computer, using the statistical package for the social sciences