Background: Microscopic colitis presents with chronic
diarrhoea with or without abdominal pain. Microscopic
colitis is an important cause of chronic diarrhoea. It can
be distributed throughout the colon, as well as limited to
the right colon. Microscopic colitis is associated with coeliac disease. We studied the prevalence and distribution of microscopic colitis in patients with diarrhoea and normal colonoscopy and we studied the association with coeliac disease.
Methods: Colonoscopy was performed. Biopsies were taken from every segment of the colon. Lymphocytic colitis was defined as the presence of more than 20 lymphocytes per 100 epithelial cells and collagenous colitis was defined as thickening of the basal membrane of more than 10 μm.
Upper endoscopy was performed if upper intestinal
symptoms were present. If this was the case, small bowel biopsies were taken.
Results: Microscopic colitis was found in 13 out of
103 patients. The distribution was diffuse throughout
the colon in ten and restricted to the right colon in three
patients. In seven patients, upper endoscopy was
performed. Marsh I/II lesions were found in six out of
Conclusion: Microscopic colitis was limited to the right
colon in 23% of patients. Biopsies of macroscopically
normal colonic mucosa in patients with diarrhoea is mandatory