CLINICO-PATHOLOGICAL FEATURES AND TREATMENT OF KAYEXALATE RELATED COLONIC NECROSIS : a case presentation and review  F. Cherbanyk , H.L. Chan , M. Dimitrief , O. Martinet, E. Pezzetta Service de Chirurgie Hôpital RIVIERA-CHABLAIS site Montreux Introduction : Sodium polystyrene sulfonate (KAYEXALATE) administration, with or without sorbitol adjunction, is a well known option in the management of end stage renal failure. Intestinal injury and particularly colonic necrosis has been described as a significant and serious possible adverse effect of this kind of treatment when administered orally or even as enema.   Methods :we wish to report here and illustrate the full-blown clinical picture of a patient presenting with kayexalate related colonic necrosis with particular emphasis on clinico-pathological aspects of the disorder.     Case presentation : a 73 years-old patient with Wegener disease related end stage renal failure developed diffuse and intense abdominal pain ; a CT scan revealed a significant pneumoperitoneum. An exploratory laparoscopy was undertaken revealing a small and circumscribed zone of perforation involving the sigmoid colon ; an open segmental sigmoid resection was performed. In the post operative phase the patient presented a multi-organ failure with subsequent death. The anatomopathological evaluation of the resected colon astonishingly revealed a colitis with areas of inflammatory ulcerations up to a transmural colitis and signs of perforation with multiple crystals within the intestinal wall. Conclusions : colonic toxicity and related necrosis are well documented, rare and often underrecognized adverse effects that may result from the administration of cation exchange resins, such as KAYEXALATE, which are routinely used in the mangement of hyperkalemia. These significant and sometimes lethal complications must therefore be kept in mind when prescribing such agents.