This report describes six children with spina bifida who have experienced a total of 13 episodes of generalized hives, angioedema and in two cases, anaphylactoid reactions immediately following saline enema infusions. The enemas were administered using a kit comprised of a plastic bag, tubing, and rectal end-piece. The reactions always occurred with the first use of new kits. A third child developed a systemic reaction with only the rectal end-piece in situ and without infusion of fluid. An in-hospital challenge using a new end-piece in one patient, who was clinically the most sensitive, produced an acute anaphylactoid reaction implicating the end-piece as the most likely source of the problem. The definitive mechanism(s) of the reactions and the agent(s) responsible for them presently remain unknown.