Microscopic Colitis Gastroenterology Darrell S. Pardi, Ciarán P. Kelly  Gastroenterology  Volume 140, Issue 4, Pages 1155-1165 (April 2011) DOI: 10.1053/j.gastro.2011.02.003 Copyright © 2011 AGA Institute Terms and Conditions

Figure 1 Increasing incidence of lymphocytic and collagenous colitis from 1985 to 2001. Reprinted with permission from Pardi et al.21 Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions

Figure 2 Lymphocytic colitis, characterized by increased numbers of intraepithelial lymphocytes and inflammatory infiltrate in the lamina propria. Courtesy of Thomas C. Smyrk, MD, Department of Pathology, Mayo Clinic Rochester. Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions

Figure 3 Collagenous colitis, characterized by a thickened subepithelial collagen band with entrapped capillaries. In normal colon biopsy specimens, the collagen band is 5–7 μm thick. Courtesy of Thomas C. Smyrk, MD, Department of Pathology, Mayo Clinic Rochester. Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions

Figure 4 Acute inflammation in a biopsy showing collagenous colitis. Features include cryptitis (thick arrow) and a giant-cell reaction to a damaged crypt (thin arrow). Courtesy of Thomas C. Smyrk, MD, Department of Pathology, Mayo Clinic Rochester. Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions

Figure 5 Surface epithelial damage in collagenous colitis. In this example, the surface epithelial cells have cuboidal shapes and separation from the basement membrane. Courtesy of Thomas C. Smyrk, MD, Department of Pathology, Mayo Clinic Rochester. Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions

Figure 6 Management of microscopic colitis. The initial approach to treatment is guided by the severity of symptoms. Alternatives to budesonide for patients who do not respond include bile acid binders, aminosalicylates, and prednisone. For recurrent disease after a successful course of budesonide, treatment options include immunomodulators or long-term low-dose budesonide. Very few patients require surgery for medically refractory microscopic colitis. Gastroenterology 2011 140, 1155-1165DOI: (10.1053/j.gastro.2011.02.003) Copyright © 2011 AGA Institute Terms and Conditions