Constipation in term infants is actually quite
rare. Babies usually pass the thick tarry stool
called meconium within 24 hours of life. We do not include any meconium passed in utero,
as this is often caused by other reasons, such as fetal distress. So passing meconium
in utero does not preclude neonatal constipation. If a term newborn has not passed meconium
by 24-48 hours, this is quite concerning and there are three things that you cannot afford
to miss in these patients – an imperforate anus, a bowel obstruction, and poor feeding
leading to failure to thrive. An Imperforate Anus
Stool cannot be passed if the pathway out is blocked. A thorough newborn examination
looking at the location of the anus related to the base of the scrotum or vagina, and
ensuring the anus is patent makes this diagnosis relatively straight forward.
Urgent pediatric surgical referral is necessary to create a new anus.
A Bowel Obstruction When there is no stool output and it is accompanied
by vomiting and/or abdominal distension, bowel obstruction must be considered.
The most common cause of bowel obstruction in neonates is Hirschsprung’s Disease. In
this condition, stool becomes stuck and unable to move because a section of the bowel is
missing the nerves required for peristalsis. Urgent pediatric surgical consultation is
indicated if Hirschsprung’s Disease is suspected. Remember that Cystic fibrosis can sometimes
cause bowel obstruction in the first several days or weeks of life. Consider a diagnosis
of cystic fibrosis even more strongly if constipation is associated with failure to thrive and/or
respiratory symptoms. Lastly, if you see a neonate who is vomiting
green (bile), it is never normal and represents a bowel obstruction that requires urgent surgical
intervention. Poor Feeding leading to Failure to Thrive
Just like older people, babies need plenty of fluids to maintain healthy bowels.
Babies who do not gain weight well, whether due to maternal, baby, or supply reasons,
may develop constipation. Always remember to obtain a thorough newborn
feeding history and check the baby’s weight. The treatment in this situation is ensuring
that the baby gets enough nutrition to create and pass stools and gain appropriate weight.