Rectal biopsy for Hirschsprung's disease--are we performing too many?

Background: Rectal biopsy is considered the gold standard for the diagnosis of Hirschsprung's disease. The aim of this study was to evaluate the outcome of rectal biopsies performed in our institution, and to determine whether we are performing an adequate number of biopsies in patients presenting with features suggestive of this disease.

Methods: A retrospective analysis was conducted of patients who underwent rectal biopsy to exclude Hirschsprung's disease over a seven year period between 2000 and 2006. The histological diagnosis of Hirschsprung's disease was made using haematoxylin and eosin as well as acetylcholinesterase on frozen section. Patients were grouped into three age categories: neonates (group A), infants (group B) and those over 1 year of age (group C). The results of the biopsies were compared between groups.

Results: A total of 668 patients underwent rectal biopsy. 18 samples were insufficient. Based on the histological studies of 650 suitable samples, 73 (11%) were positive and 577 (89%) were negative for Hirschsprung's disease. Of the 73 positive biopsies, 34 (47%) were from group A, 20 (27%) from group B and 19 (26%) from group C. The percentage of positive biopsies was much higher in group A with 29% (34 out of 118) compared to group B with 15% (20 out of 135) and group C with 5% (19 out of 395). Three complications of minor rectal bleeding occurred.

Conclusions: With 3 complications and 18 insufficient samples out of 668, rectal biopsy is a safe procedure and remains the gold standard for the diagnosis of Hirschsprung's disease, despite the large number of negative biopsies. Contrary to some reports in the literature which question the need for rectal biopsy in those presenting after the neonatal period, 53% of our positive diagnoses were made in children presenting after this period, with 19 positive biopsies out of 395 (5%) performed in children above the age of 1 year.