%0 Journal Article %T Microscopic Colitis: Epidemiology, Pathophysiology, Diagnosis and Current Management¡ªAn Update 2013 %A Martin Alexander Storr %J ISRN Gastroenterology %D 2013 %R 10.1155/2013/352718 %X Microscopic colitis is a common cause of chronic diarrhea. Over the last years the incidence and the prevalence of microscopic colitis are rising and this rise is largely attributed to a rising awareness, and concomitantly an increasing number of diagnoses are made. Patients with microscopic colitis report watery, nonbloody diarrhea of chronic, intermittent, or chronic recurrent course. Following an unremarkable physical examination the diagnosis of microscopic colitis is made by colonoscopy, which shows essentially a normal colonic mucosa. Biopsies taken during the colonoscopy procedure will then finally establish the correct diagnosis. Histological workup can then confirm a diagnosis of microscopic colitis and can distinguish the two distinct histological forms, namely, collagenous colitis and lymphocytic colitis. Presently both forms are diagnosed and treated in the same way; thus the description of the two forms is not of clinical value, though this may change in future. Depending on the patients age and gender 10¨C30% of patients investigated for chronic diarrhea will be diagnosed with microscopic colitis if biopsies are taken. Microscopic colitis is most common in older patients, especially in female patients and is frequently associated with autoimmune disorders and the consumption of several drugs. This review summarizes the present knowledge of the epidemiology, the pathophysiology, and the diagnosis of microscopic colitis and discusses the former and the present treatment options. 1. Introduction Microscopic colitis is a relatively recent term used for a group of gastrointestinal diseases where chronic watery diarrhea is the leading symptom. The term was coined approximately 30 years ago in a journal case report on a patient with chronic diarrhea. In this specific case report, where the diagnostic workup and the clinical context as well as therapeutic decisions were discussed, the mild inflammatory changes seen by the pathologist in the colonic mucosa where judged as being not-related [1]. The term collagenous colitis is actually a few years older and collagenous colitis now stands for one major form of microscopic colitis [2]. The more recent term, namely, lymphocytic colitis, stands for the other defined major form of microscopic colitis [1]. It is an ongoing matter of debate whether lymphocytic colitis and collagenous colitis really are one disease and should be discussed together as microscopic colitis or whether they are two different diseases that just share some features like clinical presentation and are presently treated in the same %U http://www.hindawi.com/journals/isrn.gastroenterology/2013/352718/