<prompt> Investigation of choice in Hirschsprungs disease is:Rectal manometryRectal examinationRectal biopsyBa enema  <response>: Ans. c Rectal biopsyRef: Schwartz 10th edition, Page 1625 Rectal biopsy must be taken 1,2 and 3cm above the dentate line in children under IV sedation. In newborn no anesthesia is needed as biopsy is taken from pain insensitive area and hence done bedside. 