Kayexalate: a new cause of neonatal bowel opacification.

Two cases of neonatal bowel opacification secondary to oral and rectal administration of Kayexalate (sodium polystyrene sulfonate) are presented. Abdominal radiographs of both infants showed a faint, homogeneous increase in density within the bowel lumen. The properties of Kayexalate and its possible interactions with the gastrointestinal tract are discussed. Kayexalate administration should be included in the differential diagnosis of bowel opacification.