Published online Jul 14, 2013. doi: 10.3748/wjg.v19.i26.4252
Revised: May 4, 2013
Accepted: May 16, 2013
Published online: July 14, 2013
Lymphocytic and collagenous colitis are forms of microscopic colitis which typically presents in elderly patients as chronic watery diarrhea. The association between microscopic colitis and inflammatory bowel disease is weak and unclear. Lymphocytic colitis progressing to ulcerative colitis has been previously reported; however there is limited data on ulcerative colitis evolving into microscopic (lymphocytic or collagenous) colitis. We report a series of six patients with documented ulcerative colitis who subsequently were diagnosed with collagenous colitis or lymphocytic colitis suggesting microscopic colitis could be a part of the spectrum of inflammatory bowel disease. The median duration of ulcerative colitis prior to being diagnosed with microscopic colitis was 15 years. We noted complete histological and/or symptomatic remission in three out of six cases while the other three patients reverted back into ulcerative colitis suggesting lymphocytic or collagenous colitis could present as a continuum of ulcerative colitis. The exact molecular mechanism of this histological transformation or the prognostic implications is still unclear. Till then it might be prudent to follow up these patients to assess for the relapse of inflammatory bowel disease as well as for dysplasia surveillance.
Core tip: Lymphocytic colitis (LC), together with collagenous colitis (CC) is a part of the spectrum of “microscopic colitis” (MC) characterized by profuse non-bloody watery diarrhea, without endoscopic or radiological lesions, but with histological abnormalities. The association between LC and inflammatory bowel disease (IBD) is weak and unclear. The case reports of CC progressing to ulcerative colitis (UC) and vice versa has been previously reported but however to our knowledge we report the first case series of six patients with chronic UC subsequently developing into CC or LC suggesting MC could be a part of the spectrum of IBD.