<prompt> True statement regarding Hirschsprungs disease-Giant ganglia are presentMucosa is involved and show foldingsManometry excludes the diseaseRectal biopsy is contraindicated in infants.  <response>: Anorectal manometry is a useful screening procedure for the diagnosis of Hirschsprungs disease. A normal response in course of manometric evaluation precludes the diagnosis of Hirschsprungs disease.However, the confirmation of diagnosis in case of Hirschsprungs disease is done by rectal biopsy.Pathogenesis of Hirchsprung diseaseThe enteric neuronal plexuses develop from neural crest cells, which migrate into the bowel wall during development, mostly in a cephalad to caudad direction.Hirschsprung disease results when the migration of neural crest cells arrests at some point before reaching the anus inappropriate premature death.This produces an intestinal segment that lacks both Meissner submucosal and Auerbach myenteric plexus.Loss of enteric neural coordination leads to functional obstruction and intestinal dilation proximal to the affected segment. 