Kayexalate-induced colonic ulcer

A 61-year-old male presents to the emergency room with complaints of fatigue, dizziness and bright red blood per rectum (BRBPR) for 2 days. Past medical history was significant for gastroesophageal reflux disease, non-steroidal antiinflammatory drug (NSAID) induced ulcer, and end-stage renal disease (GFR < 30) status post 2 failed renal grafts. Pertinent medications include pantoprazole and sodium polystyrene sulfonate in sorbitol (Kayexalate 30 g/d orally). On esophagogastroduodenoscopy (EGD) there was a single shallow, flat, non-bleeding gastric ulcer (3mm) in the pre-pyloric region of the stomach with no stigmata of bleeding. A colonoscopy was performed showing evidence of colitis and localized ulcerations in the cecum which were biopsied. Histopathology revealed basophilic, nonpolarizable, rhomboid-like crystals without evidence of necrosis.