<prompt> Most serious side effect with sodium polystyrene sulfonate -Intestinal perforationRebound hyperkalemiaCardiac arrestRespiratory arrest  <response>: Ans. is a i.e., Intestinal perforation o Sodium polystyrene sulfonate SPS exchanges Na for K in the gastrointestinal tract and increases the fecal excretion of K.It causes slow increase in serum K concentration.The full effect may take up to 24 hours and usually requires repeated doses every 4-6 hours.Intestinal necrosis is the most serious complication of SPS. 