Chronic diarrhoea is a frequent complaint in clinical
practice. Microscopic colitis is the cause of this symptom
in 10% of these cases and the prevalence is rising. To
exclude microscopic colitis a colonoscopy with multiple
biopsies of different regions of the colon is mandatory. A
sigmoidoscopy alone is insufficient. Two histopathological
types of microscopic colitis can be distinguished:
collagenous colitis and lymphocytic colitis. Nowadays, there is sufficient evidence to recommend budesonide as the first-choice treatment. Bismuth can also be recommended, but this drug is not easily available in the Netherlands. Evidence of efficacy of other drugs is scant.