Assessment for Hirschsprung disease in infants and young children

HAEC: Hirschsprung-associated enterocolitis.
* A moderate level of suspicion is also warranted for neonates with well-documented delay in passing meconium but no other signs, symptoms, or risk factors for Hirschsprung disease. Practice varies regarding the evaluation of these infants. At a minimum, they should undergo a careful physical examination and exclusion of other causes of delayed passage of meconium, including anorectal malformations, and should be closely observed and evaluated promptly for Hirschsprung disease if they develop symptoms of constipation or abdominal distension.
¶ The "squirt sign" is a forceful expulsion of gas and stool as the finger is withdrawn from the anus after the digital rectal examination, particularly in infants.
Δ For more details on the evaluation and management of HAEC, refer to UpToDate content on emergency complications of Hirschsprung disease.
◊ In our practice, we generally perform a contrast enema rather than suction biopsy as the initial diagnostic procedure; if a clear transition zone is seen, the study is virtually pathognomonic of Hirschsprung disease and helps the surgeon plan the level of resection preoperatively. We always confirm the diagnosis by biopsy even when the contrast enema shows typical features of Hirschsprung disease. Even if a transition zone is not seen, Hirschsprung disease cannot be entirely excluded. The contrast enema may have false-negative results if performed within 24 hours of a digital rectal examination.
§ Some providers proceed to an anorectal manometry and/or rectal suction biopsy without a contrast enema. If ganglia are seen in an appropriately performed suction biopsy, Hirschsprung disease is excluded. Lack of ganglia on the suction biopsy is suspicious for Hirschsprung disease, but the diagnosis may have to be confirmed by a full-thickness rectal biopsy if the pathologist considers the suction biopsy to be an inadequate sample. Similarly, normal results of anorectal manometry can exclude Hirschsprung disease, but abnormal results should be confirmed by biopsy. Anorectal manometry is less accurate in infants under 1 month of age.