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
Anorectal manometry
Rectal biopsy
Lower G1 contrast study
Trypsin estimation
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.