Investigation of choice in hirschsprug's disease is -
Definitive diagnosis is made by rectal biopsy. The histopathology of Hirschprung's disease is the absence of ganglion cells in the nerve plexus, presence of hypertrophied nerve bundles and increased acetykholinesterase-positive nerve fibres.
Rectal manometry
Rectal examination
Rectal biopsy
Ba enema