An infant with chronic constipation since birth and abdominal distension should be evaluated for Hirschsprung disease. Which diagnostic workup is used to confirm this diagnosis?

• A. Abdominal ultrasound
• B. Rectal suction biopsy only
• C. Barium enema and rectal manometry
• D. Barium enema, rectal manometry, and rectal suction biopsy

Answer: (D)

Hirschsprung disease causes a functional obstruction from absence of enteric ganglion cells in the distal bowel. To confirm this, you need both evidence of a distal, nonrelaxing segment and a tissue diagnosis of missing ganglion cells.

A contrast enema (barium enema) helps map the problem by showing a transition from a narrow, aganglionic distal segment to a dilated proximal gut. It guides where to biopsy and supports the suspicion, but it isn’t definitive on its own.

Rectal suction biopsy provides the definitive histologic confirmation by demonstrating absence of ganglion cells in the submucosa (and myenteric plexuses), which is the hallmark of the disease.

Rectal manometry adds useful supportive information by testing for the rectoanal inhibitory reflex; its absence is common in Hirschsprung, but it is not diagnostic by itself and is best used as an additional test.

Thus, using barium enema to identify the affected area, rectal manometry to assess reflexes, and rectal suction biopsy to confirm the histology represents the comprehensive approach to establish the diagnosis.