Diagnosis and treatment of microscopic colitis

Microscopic colitis (MC) designates two types of chronic diarrhea diseases, which are lymphocytic colitis and collagenous colitis. The prevalence of microscopic colitis is increasing in both Western and Eastern countries, possibly due to the high incidence of colonoscopic survey in chronic diarrhea patients. Although the overall prognosis of MC patients is mostly good, it should be noted that appropriate diagnosis and choice of treatment is required to assure a good clinical outcome for MC patients. Also, a certain population of MC patients may take a severe and refractory clinical course, and thus require advanced clinical care using medications supported by less evidence. In this review, we would like to feature the essential points regarding the diagnosis of MC, and also describe the current standard of treatments for MC patients. In addition, we would like to add some findings from the national survey and research carried out in Japan, to compare those data with the western countries.