This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastro Intestinal System, Subject name: Pediatrics
Which of these disorders in neonates can best be excluded or diagnosed by anorectal manometry? 
Select and explain. 
A. Hypertrophic pyloric stenosis, B. Duodenal atresia, C. Meconium plug syndrome, D. Hirschsprung's disease
D: Hirschsprung's disease
Answer: D: Hirschsprung's disease 
Explanation: Ans. D. Hirschsprung's diseaseAnorectal manometry should ideally be performed in all newborns with symptoms of lower bowel obstruction. This technique is useful in assessment of changes in anal pressure which are recorded during and after rectal distention. It is most helpful for diagnosing or excluding Hirschsprung's disease.