Microscopic Colitis

Abstract

Microscopic colitis is an increasingly common cause of chronic diarrhea, and often causes abdominal pain and weight loss. The colonic mucosa appears normal or nearly normal endoscopically, and the diagnosis is made in the appropriate clinical setting when there is intraepithelial lymphocytosis and a mixed lamina propria inflammatory infiltrate. The 2 subtypes, collagenous and lymphocytic colitis, are similar clinically and histologically, and are distinguished by the presence or absence of a thickened subepithelial collagen band. Many potential pathophysiologic mechanisms have been proposed, but no convincing unifying mechanism has been identified. There are many anecdotal reports on treatment, but few controlled trials have been performed in these patients, although a systematic approach to therapy often leads to the satisfactory control of symptoms.

Mucosal Immune Activation in Irritable Bowel Syndrome: Gender-Dependence and Association With Digestive Symptoms

“…Patients complained of chronic watery diarrhea and normal ndings on colonoscopy, but with histological evidence of in ammation on colonic biopsies, characterized by intraepithelial lymphocytosis (>20 lymphocytes / 100 epithelial cells) and an in ammatory in ltrate in the lamina propria (21) .…”

Is Microscopic Colitis a Drug-induced Disease?

“…MC is characterized by the combined presence of watery diarrhea, a macroscopically normal ileocolonoscopy and typical microscopic findings. 1 The histologic changes of MC comprise an increased number of intraepithelial CD8 + T lymphocytes, exceeding 20 per 100 surface epithelial cells, accompanied by superficial epithelial damage and a variable inflammatory infiltrate in the lamina propria. In addition, in CC, a thickened subepithelial collagen band, which exceeds 10 mm, is present.…”

Differences in the T-bet and GATA-3 expression patterns between lymphocytic colitis and coeliac disease

“…Furthermore, the therapy differs from that to coeliac disease. Gluten-free diet is only in some cases helpful [19], but steroids are often effective. The situation in CD is clear as it has been established as a Th1-mediated inflammatory reaction [12,13].…”