Collagenous Inflammatory Mucosal Diseases of the Gastrointestinal Tract

A new group of collagenous inflammatory disorders of the gastricand intestinal mucosa has been described in the past two decades. These entitiesappear to be characterized by a distinct histopathologic lesion in the subepithelialregion of the lamina propria. Functional alterations may also occur, presumablyrelated to collagen deposition and the associated inflammatory process. Collagenoussprue is characterized by progressive and unrelenting malabsorption; alethal outcome has usually been described, possibly reflecting the site of collagendeposition and the critical role of the small bowel for maintenance of a normalnutritional state. In contrast, collagenous colitis is characterized by persisting orepisodic watery diarrhea; clinical impairment appears to be less severe but theentity is not rare, possibly reflecting its colonic localization. Most recently,collagenous gastritis, possibly accompanied by a functional reduction in acidsecretion and impaired gastric emptying, has been recognized. Further definitionof these entities is still required, particularly in relation to etiology, pathogenesisand effective therapy