Microscopic Colitis: An Interesting Case Report

Abstract

Microscopic colitis is a chronic inflammatory disease of the large intestine characterized by chronic diarrhea.By endoscopy, the colonic mucosa appears normal.It is diagnosed by intestinal biopsy and is histologically subdivided into two types: lymphocytic and collagenous colitis. Lymphocytic colitis is characterized by intraepithelial lymphocytes and collagenous colitis appears as a colonic subepithelial collagen band >10 micrometers in thickness.A 72-year-old woman presented to the clinic complaining of intermittent diarrhea for the past 12 years.She initially had occasional episodes of watery diarrhea that were occurring after eating that were not frequent and did not cause significant discomfort.She was doing well without treatment until 8 years ago when it became more frequent and the diarrhea became associated with episodes of cramping abdominal pain.The patient was previously diagnosed with Lymphocytic colitis and had been tried on Asacol and Enterocort without much improvement in diarrhea.She was also treated with Prednisone with significant improvement in diarrhea.After she developed worsening diarrhea a colonoscopy was performed which appeared grossly normal with normal pathology.She subsequently developed episodes of diarrhea alternating with constipation and was diagnosed with IBS and was initiated on treatment with Bentyl and then subsequently amitriptyline.However, symptoms would intermittently recur. In addition, patient developed multiple episodes of diarrhea after treatment with Zithromax for an upper respiratory infection. Repeat colonoscopy with biopsies performed revealed intraepithelial lymphocytes.Budesonide was added with significant improvement in her symptoms.She is now being treated with budesonide and amitriptyline and has been doing well. She is a smoker who has been smoking for many years.Most recent colonoscopy performed 1 year ago showed congested mucosa in the ascending colon and in the cecum.Previous colonoscopy performed 3 years earlier showed spontaneous bleeding mucosa in the ascending colon and in the cecum.Biopsies performed during both colonoscopies showed intraepithelial lymphocytes.Microscopic colitis appears as normal intestinal mucosa by colonoscopy. It is diagnosed histologically by biopsy.In this case, there were abnormalities in the intestinal mucosa seen by colonoscopy in a patient with microscopic colitis in the same areas of the colon with intraepithelial lymphocytes found by biopsy.Figure: Recent colonoscopy showed congested mucosa in the ascending colon and cecum.Figure: Spontaneous bleeding mucosa in the ascending colon and cecum on colonoscopy done 3 yrs prior.