title: Clinical Characteristics of Microscopic Colitis in Korea: Prospective Multicenter Study by KASID.
abstract: OBJECTIVE
  Microscopic colitis (MC) encompasses collagenous and lymphocytic colitis and is characterized by chronic diarrhea. In cases of MC, colonic mucosae are macroscopically normal, and diagnostic histopathological features are observed only upon microscopic examination. We designed a prospective multicenter study to determine the clinical features, pathological distribution in the colon and prevalence of MC in Korea.
  
  
  METHODS
  We prospectively enrolled patients having watery diarrhea no more than 3 times a day between March 2008 and February 2009. We obtained patient histories and performed colonoscopies with random biopsies at each colon segment.
  
  
  RESULTS
  A total of 100 patients with chronic diarrhea were enrolled for a normal colonoscopy and stool exam. MC was observed in 22 patients (22%) (M:F 1.2:1; mean age, 47.5 years). Of those 22 patients, 18 had lymphocytic colitis and 4 had collagenous colitis. The entire colon was affected in only 3 cases (13.6%), the ascending colon in 6 cases (27.2%), the transverse colon in 3 cases (13.6%), and the left colon in 3 cases (13.6%). More than 2 segments were affected in 7 cases (31.8%). Nonsteroidal anti-inflammatory drug-associated MCs were observed in 4 cases (18.2%), 3 of which showed improved diarrhea symptoms following discontinuation of the medication. Frequently associated symptoms were abdominal pain and weight loss. Autoimmune diseases were observed in 4 cases (18.2%). Half of the 22 patients with MC improved with conservative care by loperamide or probiotics.
  
  
  CONCLUSIONS
  In a prospective multicenter study of Korean patients with chronic diarrhea, the frequency of MC was found to be approximately 20%, similar to the percentage observed in Western countries. Therefore, the identification of MC is important for the adequate management of Korean patients with chronic diarrhea.
authors.affiliation: Department of Internal Medicine, Eulji University College of Medicine, Korea.
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Park
authors.forename: Dae Hyun
authors.initials: DH
authors.lastname: Baek
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Joo Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Suk-Kyun
authors.initials: SK
authors.lastname: Yang
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Jung
authors.forename: Byung Ik
authors.initials: BI
authors.lastname: Jang
authors.forename: Chnag Hwan
authors.initials: CH
authors.lastname: Choi
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Han
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Chung
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: You Sun
authors.initials: YS
authors.lastname: Kim