Collagenous Colitis and Inflammatory Bowel Disease: Is It a Complication or Spectrum of the Same Disease?

Abstract

Purpose: Collagenous colitis is an inflammatory mucosal disorder that results in chronic watery diarrhea without bleeding. It is characterized by a thick subepithelial collagen band and increased lymphocytes in the lamina propria of an otherwise endoscopically normal-appearing colon. It is generally benign disease, with a course that is characterized by alternating spontaneous relapses and remissions. There have been cases reported in literature in which microscopic colitis preceded Crohn's disease and ulcerative colitis. It is unclear to date if these cases are only coincidental or represent progression of disease. We report one patient who was diagnosed with collagenous colitis 2 years ago. His prior treatment included budesonide and cholestyramine intermittently. The patient presented with severe abdominal pain, weight loss, anorexia, and bloody diarrhea. Colonoscopy showed mucosal changes suggestive of ulcerative colitis; diagnosis was confirmed with biopsy interpretation. Stool studies were negative. The patient was started on intravenous solu-medrol. His symptoms improved for a few days but then again progressed to severe bloody diarrhea with abdominal pain. A flexible sigmoidoscopy was performed revealing persistent inflammatory mucosal changes. Biopsies also showed cytomegalovirus in the background of ulcerative colitis. Intravenous gancyclovir therapy was added to the medical regimen. Patient's symptoms resolved within a week and the patient was discharged home on valgancyclovir and prednisone. We report an additional case report, added to the previous six, which augments the theory that collagenous colitis could be a part of the spectrum of inflammatory bowel disease (Table 1).Table 1: Reported cases of collagenous colitis evolving into ulcerative colitis