Update on idiopathic colitidesStrobel, Sebastian; Abreu, Maria T.Current Opinion in Gastroenterology: January 2013 - Volume 29 - Issue 1 - p 60–65 doi: 10.1097/MOG.0b013e32835abc93 LARGE INTESTINE: Edited by Ciarán P. Kelly Abstract Author Information Purpose of review This article summarizes the latest developments for three types of idiopathic colitis: ulcerative colitis, Crohn's disease, and microscopic colitis. Recent findings Crohn's disease and ulcerative colitis are highly related genetically. Colonoscopy remains the gold standard for making a diagnosis. The addition of chromoendoscopy can aid in identification and removal of colonic dysplasia in both disorders. The therapy for ulcerative colitis and Crohn's disease has been transformed with the introduction of anti-TNF treatment. For ulcerative colitis, recent data show that prolonged use of infliximab is effective, well tolerated and that early mucosal healing is associated with decreased risk of colectomy. There is no evidence of a significant increased risk for anti-TNF-induced malignancies. Combination therapy with azathioprine and infliximab for ulcerative colitis has now been shown to be superior to monotherapy. Natalizumab is effective in anti-TNF failures and patients can be risk stratified for progressive multifocal leukoencephalopathy by testing for John Cunningham virus antibodies. Microscopic colitis can often be related to medications, and symptoms may be worsened by coexisting celiac disease. Summary Combination therapy with an anti-TNF and a thiopurine is currently the most effective treatment for moderate-to-severe Crohn's disease or ulcerative colitis. Stem cell therapy for perianal fistulas in patients with Crohn's disease is a promising new therapy approach. Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA Correspondence to Maria T. Abreu, MD, Division of Gastroenterology, Department of Medicine, University of Miami Miller School of Medicine, Gautier, 510 (D-149), 1011 NW 15th Street, Miami, FL 33136, USA. Tel: +1 305 243 6404; fax: +1 305 243 6125; e-mail: MAbreu1@med.miami.edu © 2013 Lippincott Williams & Wilkins, Inc.