From the Guidelines
The primary diagnostic test for Hirschsprung disease is rectal biopsy, which is considered the gold standard for diagnosis. This is because rectal biopsy can directly assess the presence or absence of ganglion cells in the submucosal and myenteric plexuses, a key feature of Hirschsprung disease 1. Other diagnostic tests that may be used include contrast enema, which can show a transition zone between the narrowed aganglionic segment and the dilated normal bowel, and anorectal manometry, which can demonstrate failure of the internal anal sphincter to relax with rectal distention.
- Key features of Hirschsprung disease that can be identified through diagnostic tests include:
- Absence of ganglion cells in the submucosal and myenteric plexuses on rectal biopsy
- Hypertrophied nerve trunks with increased acetylcholinesterase staining on rectal biopsy
- Failure of the internal anal sphincter to relax with rectal distention on anorectal manometry
- Transition zone between the narrowed aganglionic segment and the dilated normal bowel on contrast enema
- Additional tests that may be used to evaluate for complications or associated conditions include abdominal X-rays to evaluate for intestinal obstruction and genetic testing for associated syndromes.
- It is essential to note that early diagnosis of Hirschsprung disease is crucial to prevent serious complications such as toxic megacolon, enterocolitis, and growth failure if left untreated, as highlighted in the context of evaluating vomiting in infants where imaging plays a role in differentiating between various pathologies including Hirschsprung disease 1.
From the Research
Diagnostic Tests for Hirschsprung Disease
The primary diagnostic tests for Hirschsprung disease include:
- Rectal biopsy, which is considered the gold standard for diagnosis 2, 3, 4, 5
- Barium enema, which can be used as an initial screening test, but a normal result does not exclude Hirschsprung disease 6
- Rectal manometry, which can be used to support the diagnosis of Hirschsprung disease, but is not as sensitive as rectal biopsy 6
Types of Rectal Biopsy
There are different types of rectal biopsy that can be used to diagnose Hirschsprung disease, including:
- Suction rectal biopsy, which is a less invasive procedure, but may have a higher rate of inadequate samples in older patients 2
- Incisional rectal biopsy, which is a more invasive procedure, but may have a lower rate of inadequate samples 2
- Excisional biopsy, which can be used to diagnose Hirschsprung disease with a high degree of accuracy, especially when performed at the anorectal line 4
Immunostaining for Diagnosis
Immunostaining for calretinin, S100 protein, and protein gene product 9.5 can be used to support the diagnosis of Hirschsprung disease, with high sensitivity and specificity rates 3
Importance of Expert Pathologic Evaluation
A well-executed rectal biopsy with expert pathologic evaluation of the specimen is crucial for the accurate diagnosis of Hirschsprung disease 5