A newborn baby has not passed meconium for 48 hours since bih. She has vomiting and distension of abdomen. The most appropriate investigation for evaluation would be
C i.e. Lower GI contrast study Lower GI contrast study confirms the diagnosis & indicate the type of involvement, in cases of lower intestinal obstruction causing failure to pass meconium timelyQ.
Anorectal manometry
Rectal biopsy
Lower G1 contrast study
Trypsin estimation