*Department of Internal Medicine, Eulji University College of Medicine, Korea.
†Department of Internal Medicine, Yonsei University College of Medicine, Korea.
‡Department of Internal Medicine, Seoul National University College of Medicine, Korea.
§Department of Internal Medicine, University of Ulsan College of Medicine, Korea.
∥Department of Internal Medicine, Ehwa Womans University School of Medicine, Korea.
¶Department of Internal Medicine, Yeungnam University College of Medicine, Korea.
#Department of Internal Medicine, Chung Ang University College of Medicine, Korea.
**Department of Internal Medicine, Hanyang University College of Medicine, Korea.
††Department of Internal Medicine, Sungkyunkwan University School of Medicine, Korea.
‡‡Department of Internal Medicine, Hallym University College of Medine, Korea.
§§Department of Internal Medicine, Inje University College of Medicine, Korea.
∥∥Korean Association for the Study of the Intestinal Disease (KASID), Korea.
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.
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.
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.
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.