Diagnosis and management of microscopic colitis: current perspectives

Abstract

Collagenous colitis and lymphocytic colitis, together constituting microscopic colitis, are common causes of chronic diarrhea. They are characterized clinically by chronic nonbloody diarrhea and a macroscopically normal colonic mucosa where characteristic histopathological findings are seen. Previously considered rare, they now have emerged as common disorders that need to be considered in the investigation of the patient with chronic diarrhea. The annual incidence of each disorder is five to ten per 100,000 inhabitants, with a peak incidence in 60- to 70-year-old individuals and a predominance of female patients in collagenous colitis. The etiology and pathophysiology are not well understood, and the current view suggests an uncontrolled mucosal immune reaction to various luminal agents in predisposed individuals. Clinical symptoms comprise chronic diarrhea, abdominal pain, fatigue, weight loss, and fecal incontinence that may impair the patient's health-related quality of life. An association is reported with other autoimmune disorders, such as celiac disease, thyroid disorders, diabetes mellitus, and arthritis. The best-documented treatment, both short-term and long-term, is budesonide, which induces clinical remission in up to 80% of patients after 8 weeks' treatment. However, after successful budesonide therapy is ended, recurrence of clinical symptoms is common, and the best possible long-term management deserves further study. The long-term prognosis is good, and the risk of complications, including colonic cancer, is low. We present an update of the epidemiology, pathogenesis, diagnosis, and management of microscopic colitis.

Keywords: budesonide; chronic diarrhea; collagenous colitis; lymphocytic colitis; microscopic colitis.

Figure 1

(A) Normal colonic mucosa. (B) Characteristic findings of collagenous colitis: detached and damaged epithelial cells (a), lamina propria inflammation (b), and thickened collagen layer (c). (C) Characteristic findings of lymphocytic colitis: epithelial cell damage with intraepithelial lymphocytosis (a) and inflammation in the lamina propria (b). Hematoxylin and eosin (HE) staining.

Figure 2

Algorithm for the treatment of microscopic colitis proposed by the European Microscopic Colitis Group. Note: Reprinted with permission from Elsevier: © 2012 Reproduced from Münch A, Aust D, Bohr J, et al. Microscopic colitis: current status, present and future challenges: statements of the European Microscopic Colitis Group. J Crohns Colitis. 2012;6(9):932–945. Abbreviation: MC, microscopic colitis.