This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A 6 months old child woke up in night, crying with abdominal pain, which got relieved on passing red stool. What is the most likely diagnosis? 
Select and explain. 
A. Meckel's diveiculum, B. Intussusception, C. Malrotation, D. Intestinal obstruction
B: Intussusception
Answer: B: Intussusception 
Explanation: Ans. b. Intussusception