<prompt> Most common cause of hematochezia in children isRectal polypMeckels diveiculumNecrotizing enterocolitisAcute gastritis  <response>: Serious causes of hematochezia in the neonate include necrotizing enterocolitis and midgut volvulus. A wide variety of causes of hemorrhage occur as children grow older. Causes relatively unique to children are intussusception, Meckels diveiculum, and juvenile polyps Ref Davidson edition23rd pg 809 