title: Collagenous colitis: pathogenesis and management.
abstract: BACKGROUND
  Collagenous colitis is a rare disease of unknown etiology that primarily affects middle-aged women. It presents with chronic watery diarrhea and thickening of the subepithelial collagen layer of the colonic mucosa in the absence of endoscopic abnormalities.
  
  
  OBJECTIVE
  This study was undertaken to review the current literature on clinical course, pathology, diagnosis, and current management of collagenous colitis.
  
  
  RESULTS
  Collagenous colitis is an inflammatory disease of the colon, clinically characterized by a waxing and waning course of watery diarrhea, an inflammatory infiltration of the colonic mucosa, and a thickening of the subepithelial collagen layer. Its pathogenesis remains unclear, but there is evidence for an inflammatory process triggered possibly by an uncommon luminal agent. Diagnosis is established by colonic biopsies; in the setting of normal colonic mucosa, the disorder is primarily managed medically with virtually no role for surgery.
  
  
  CONCLUSIONS
  Pathogenesis of collagenous colitis remains unclear. Current data favor an inflammatory etiology, possibly involving an initiating luminal insult. Guidelines for diagnosis are being established, and medical treatment options are variably effective in the majority of cases. Very unusual refractory cases may benefit from surgical management.
authors.affiliation: Department of Surgery, St. Louis University School of Medicine, Missouri, USA.
authors.forename: I A
authors.initials: IA
authors.lastname: Halaby
authors.forename: P C
authors.initials: PC
authors.lastname: Rantis
authors.forename: A M
authors.initials: AM
authors.lastname: Vernava
authors.forename: W E
authors.initials: WE
authors.lastname: Longo
mesh_terms: D001706:Biopsy; D003092:Colitis / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000628:therapy; D003094:Collagen; D003937:Diagnosis, Differential; D004724:Endoscopy; D006801:Humans
chemical_list: D003094:Collagen