From the Research
Abdominal ultrasound is not the primary diagnostic tool for detecting Hirschsprung's disease, and a rectal biopsy is the gold standard for diagnosis. While ultrasound may show secondary findings like dilated bowel loops, it cannot directly visualize the absence of ganglion cells that characterizes this condition. The most recent and highest quality study, 1, published in 2024, supports the use of a single excisional biopsy based on the anorectal line for diagnosing Hirschsprung's disease. Other more useful diagnostic tests include contrast enema, which may show a transition zone between dilated and normal-caliber bowel, and anorectal manometry, which can demonstrate failure of the internal anal sphincter to relax with rectal distention, as shown in study 2 published in 2018.
Diagnostic Approach
The diagnostic approach for Hirschsprung's disease should prioritize rectal biopsy, as it allows pathologists to examine tissue samples for the absence of ganglion cells in the submucosal and myenteric plexuses. Study 3 published in 2016, highlights the importance of rectal biopsy in diagnosing Hirschsprung's disease. Anorectal manometry, as shown in study 4 published in 2018, can be used as a screening tool to exclude Hirschsprung's disease, but an absent rectoanal inhibitory reflex on manometry should always be followed by a rectal biopsy to confirm the diagnosis.
Key Points
- Rectal biopsy is the gold standard for diagnosing Hirschsprung's disease
- Abdominal ultrasound is not the primary diagnostic tool for detecting Hirschsprung's disease
- Contrast enema and anorectal manometry are more useful diagnostic tests than abdominal ultrasound
- A single excisional biopsy based on the anorectal line can be used for diagnosis, as shown in study 1
- Anorectal manometry can be used as a screening tool to exclude Hirschsprung's disease, but should be followed by a rectal biopsy if the rectoanal inhibitory reflex is absent, as shown in study 4