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: Pediatrics
[{'content': 'Failure to pass meconium within 48 hrs of birth in a newborn with no obvious external abnormality should lead to the suspicion of – \nSelect and explain. \nA. Anal atresia, B. Congenital pouch colon, C. Congenital aganglinosis, D. Meconium ileus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Read what Nelson says about Hirschsprung\'s disease (Congenital aganglionosis).\n"Ninety-nine per cent of full-term infants pass meconium within 48hrs of birth. Hirschsprung disease should be suspected in any fill term infant with delayed passage of stool".', 'role': 'assistant'}]