Calcium polystyrene sulfonate associated colonic mucosal injury-innocent bystander or pathogenic culprit?: a case report and literature review.

Colonic mucosal injury is rare, but may severely fatal, complications following the administration of calcium polystyrene sulfonate resins. The incidence rate is about 0.57%, administered without sorbitol, and increases to 1.8% when it is concomitant with sorbitol, especially in postoperative patients. In this case report, we demonstrated the case of a 77-year-old female with stage 3b chronic kidney disease presented with in-hospital hematochezia after 3 weeks of calcium polystyrene sulfonate administration. The colonoscopic findings showed several serpiginous ulcers with some oozing at descending and sigmoid colon. The histological findings revealed some focal inflammation and ulcerations with crystal-like materials, compatible with cation exchange resins. The recent in vitro study, explaining the pathogenesis of cation exchange resin-associated colonic mucosal injury, was also reviewed.