Abstract
Calcium polystyrene sulfonate (CPS) is one of the cation-exchange resins used to treat hyperkalemia. Constipation is well known as one of the major adverse effects in patients treated with CPS. In addition, intestinal necrosis/ulcer/perforation were reported in patients whom CPS was administered and it is requested not to use SPS-sorbitol solution. Moreover, intestinal perforation was reported in patients treated with CPS alone, and CPS itself is thought to produce intestinal perforation. In the present article, we describe a peritoneal dialysis (PD) patient with constipation induced by CPS administration who developed rectal perforation. After emergency surgery, pathologic examination demonstrated that numerous CPS crystals formed a polygon and basophilic staining was found in the necrotic tissue and inflammatory exudates of the perforated region. Furthermore, similar CPS crystals were found in inflammatory exudates on the serous membrane side of fibrinopurulent peritonitis. In addition to the findings described above, deficiency of superficial epithelium, decreased mucilage and blastogenic nuclei of crypt epithelium, atrophic crypt and slightl hemorrhage of the lamina propria mucosa were found in the colonic membrane around the perforated region. When CPS is administered, especially to patients with frequent constipation, the risk of intestinal perforation should be considered.
