Microscopic Colitis: Collagenous and Lymphocytic Colitis

The important epidemiological features of microscopic colitis are the predominance of women between 60 and 70 years of age, and that it may be diagnosed in more than 10% of patients investigated for chronic nonbloody diarrhea. Oral budesonide has the strongest evidence of effect in randomized clinical trials and is considered as a first line treatment of moderate to severe microscopic colitis. Budesonide showed effect as induction treatment as well as maintenance therapy of collagenous colitis. Lymphocytic colitis is clinically indistinguishable from collagenous colitis and the predominant symptom in 90% is chronic diarrhea, with more than 40% having watery stools. Only microscopic assessment of colonic mucosal biopsies can verify the diagnosis of collagenous or lymphocytic colitis. Patients with lymphocytic colitis and collagenous colitis are treated after an identical algorithm.