Sulfasalazine in treatment of collagenous colitis. Case report and review of the literature.

A patient is described with chronic colitis, watery diarrhea, and colonic mucosal subepithelial collagen deposition that resolved while being treated with sulfasalazine. The clinicopathologic features were consistent with collagenous colitis. Theoretically, the thickened collagen layer impairs water and electrolyte absorption, producing watery diarrhea. Such increased collagen is rarely observed in other inflammatory colon diseases and may represent a distinct morphologic reaction to various, yet undefined, injuries. Although the clinical course is benign, appropriate therapy for the debilitating symptoms is poorly understood. This report suggests that sulfasalazine may be helpful in some cases.