Pelvic floor muscle morphology and its association with non-retentive fecal incontinence following surgical treatment for hirschsprung disease in pediatric patients.

OBJECTIVE

To evaluate the relationship between postoperative bowel dysfunction and pelvic floor muscle development in children with congenital megacolon.

METHODS

Postoperative MRI data were collected from children with congenital megacolon who underwent surgery at the Department of General Surgery, Anhui Children's Hospital, between May 2007 and December 2024. MRI measurements included the position of the rectum, maximum thickness of the internal and external anal sphincters (EAS), levator ani, puborectalis, pubococcygeus, iliococcygeus, and ischiococcygeus muscles, upper rectal lumen width, and anorectal angle. Based on the 2016 Rome IV criteria for pediatric functional gastrointestinal disorders, children were classified as non-neurogenic fecal incontinence (NFI) group (Group A) or NFI group (Group B). Clinical data and MRI-derived muscle parameters were compared between groups.

RESULTS

A total of 50 children were included, with 34 in Group A and 16 in Group B. Significant differences were observed in the thickness of the EAS and puborectalis muscle between the two groups (P < 0.05). Multivariate logistic regression revealed that greater EAS thickness (OR = 0.27, 95% CI: 0.08-0.90, P = 0.03) and puborectalis thickness (OR = 0.35, 95% CI: 0.13-0.84, P = 0.02) were independent protective factors against NFI, whereas long-segment congenital megacolon (OR = 7.72, 95% CI: 1.74-34.36, P = 0.007) was an independent risk factor.

CONCLUSION

Postoperative non-retentive fecal incontinence in children with congenital megacolon may be associated with the thickness of the EAS, puborectalis muscle, and megacolon type.