<prompt> Investigation of choice to diagnosis Hirschsprugs disease is:Rectal manometryBarium enemaRectal biopsyLaparotomy  <response>: Ans. is c i.e. Rectal biopsy RepeatYou already know about the features of Hirschsprungs disease seen on contrast enema from the question asked earlierMore about the diagnosis of Hirschsprungs disease -Definitive diagnosis of Hirschsprungs disease is made by Rectal biopsy :It demonstrates following features-Absence of ganglion cells in Meissners plexus, and myenteric plexusHypertrophy of nerve trunksManometric study - Manometric studies will show a failure of relaxation of internal sphincter following rectal distension. 