The most obvious manifestation is the inability of the newborn to pass the foetal stool properly. Most normal newborns will pass faeces within 24 hours of birth and no later than 48 hours. If the newborn has not passed faeces after 48 hours, relevant investigations are needed.
In addition, due to intestinal obstruction and megacolon, newborns will also present with vomiting and abdominal distention, with bile visible in the vomitus.
The main manifestations in infants and children are persistent constipation, abdominal distention, delayed development, low protein and anaemia.