Most common cause of hematochezia in children is
Rectal polyp
Meckel's diveiculum
Necrotizing enterocolitis
Acute gastritis
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, Meckel's diveiculum, and juvenile polyps Ref Davidson edition23rd pg 809
G.I.T