A Critical Analysis of Rectal Biopsy to Exclude Hirschsprung's Disease

Most Hirschsprung's disease (HD) are diagnosed in young children with increased risk ("red flag"). Older children (>6 months) require open rectal biopsy (ORB) with its own impact on risk and resources. We investigated if "red flag", age, and sex used in combination could exclude HD.

"Red flags" are risk factors associated with HD, including neonatal bowel obstruction, genetic association, failure of passage of meconium in <48 hours, infantile constipation, distension with vomiting, or family history. All rectal biopsies (2015-2018) were reviewed for indications, methods, and histopathological findings. Logistic regression analysis was adopted to assess predictive value of "red flag," age, and sex (p < 0.05* was significant).

A total of 187 children underwent 84 suction rectal biopsies and 113 ORBs (n = 197 in total). Final histopathological diagnoses were non-HD (n = 154) and HD (n = 43). Total 78% of rectal biopsies were non-HD, of which 63% by ORB. Non-HD was associated with absence of "red flag" (49 vs. 16%*), increased age at biopsy (22 months vs. 28 days*), >6 months old (62 vs. 30%*), and female gender (54 vs. 16%*), compared with HD. In the absence of "red flag," 7/82 (9%) had HD (negative predictive value = 91%). Logistic regression analysis found absent "red flag" predicted non-HD biopsy with odds ratio 4.77 (1.38, 16.47), corrected for age and sex.

Negative rectal biopsy rate for HD is very high. The majority required ORB. Although "red flag" and gender, but not age, have strong predictive values, it is inadequate for excluding HD. This study supports the need for alternative strategies in excluding HD.