Hirschsprung Disease

A newborn who hasn't passed meconium in 48 hours and has a distended abdomen may not just be slow to stool — the nerve cells that move stool forward may be completely absent.

Hirschsprung disease (congenital aganglionic megacolon) results from the absence of parasympathetic ganglion cells in a segment of the colon, most commonly the rectosigmoid area. Without these nerve cells, the affected segment cannot perform peristalsis, creating a functional obstruction. Stool accumulates proximal to the aganglionic segment, causing massive dilation of the normal bowel above it. The hallmark newborn finding is failure to pass meconium within the first 48 hours of life, accompanied by abdominal distension and bile-stained vomiting. In older infants, ribbon-like stools, chronic constipation, failure to thrive, and a distended abdomen are classic. Diagnosis is confirmed by rectal suction biopsy showing absent ganglion cells. Definitive treatment is surgical resection of the aganglionic segment (pull-through procedure). Preoperatively, nursing care focuses on maintaining NPO status, NG decompression, IV fluids, and monitoring for enterocolitis — the most dangerous complication, presenting with explosive foul-smelling diarrhea, fever, and abdominal distension. Enterocolitis is a medical emergency requiring immediate intervention.

Key Distinctions

Don't confuse Hirschsprung disease (no meconium passage, abdominal distension, ribbon-like stools) with pyloric stenosis (projectile non-bilious vomiting, olive-shaped mass, hungry infant) — both present in early life but the GI patterns are opposite directions. Students often mistake the dilated proximal segment for the diseased part — the abnormal segment is the constricted distal portion that lacks ganglion cells. The explosive diarrhea of enterocolitis looks like improvement but is actually the most lethal complication.

Clinical Pearl

No meconium in 48 hours + distended belly = think Hirschsprung. The tight segment is the sick segment — the big bowel above it is just the backup.