This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Medicine
Most common cause of hematochezia in children is 
Select and explain. 
A. Rectal polyp, B. Meckel's diveiculum, C. Necrotizing enterocolitis, D. Acute gastritis
B: Meckel's diveiculum
Answer: B: Meckel's diveiculum 
Explanation: 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