Investigation of choice in Hirschsprung's disease is:

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.