We propose that clinical remission in collagenous colitis is defined as a mean of <3 stools/day and a mean of <1 watery stool per day and disease activity to be a daily mean of ≥3 stools or a mean of ≥1 watery stool.

Vedolizumab-treated patients represent a treatment-refractory group. A long-term effect can be achieved, even beyond 1 year of treatment.

No abstract

Objective. The association between smoking and idiopathic inflammatory bowel disease is well known; smoking seems to have a diverse effect. Crohn´s disease is associated with smoking, while ulcerative colitis is associated with non-smoking. Data on smoking in microscopic colitis of the collagenous type (CC) is lacking. The aim of this investigation was to study smoking habits in collagenous colitis and to observe whether smoking had any impact on the course of the disease. Materials and Methods.116 patients (92 women) with median age of 62 years (IQR 55-73) answered questionnaires covering demographic data, smoking habits and disease activity. As control group we used data from the general population in Sweden retrieved from the National Statistics Office of Sweden, the central bureau for national socioeconomic information. Results. Of the 116 CC patients, 37% were smokers compared to 17 % of controls (p<0.001, OR 2.95). In the age group 16-44 years, 75 % of CC patients were smokers compared to 15 % of controls (p<0.001, OR 16.54). All CC smoker patients started smoking before the onset of disease. Furthermore, smokers developed the disease earlier than non-smokers -at 42 years of age (median) compared with 56 years in non-smokers (p<0.003). Although the proportion with active disease did not differ between smokers and non-smokers, there was a trend indicating that more smokers received active treatment (42% vs. 17%), p=0.078). Conclusions. Smoking is a risk factor for collagenous colitis. Smokers develop their disease more than ten years earlier than non-smokers.