This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach and Intestines, Subject name: Pediatrics
Hirschsprung disease is confirmed by - 
Select and explain. 
A. Rectal biopsy, B. Per/Rectal examination, C. Rectal manometry, D. X-ray abdomen
A: Rectal biopsy
Answer: A: Rectal biopsy 
Explanation: Ans. is 'a' i.e., Rectal biopsy Hirschsprung disease (congenital aganglionic megacoion)o Abnormal innervation of bowel begins from internal anal sphincter and extending proximally to involve variable length of gut.o M.C. cause of lower intestinal obstruction in neonates,o Male > females.o Absence of ganglion cell in bowel wall.o C/F - delayed passage of meuonium in newborn or chronic constipation,o X-ray abdoman - dilation of proximal bowel and abdominal distention,o Large faecal mass palpable per recatly.o Confirmed by rectal manometry' and rectal suction biopsy,o Rectal suction biopsy is procedure of choice.