Bowel function and features of bowel dysfunction in preschool children with anorectal malformation type rectoperineal and rectovestibular fistula.

Anorectal malformations (ARMs) of the rectoperineal and rectovestibular fistula type (RPF/RVF) generally have a good prognosis but may be accompanied by bowel dysfunction, especially constipation. Bowel dysfunction in preschoolers may persist into adolescence and adulthood, exerting a negative effect on their quality of life. This study was designed to evaluate bowel function and identify the features of bowel dysfunction in preschoolers with RPF/RVF across type and sex differences. A total of 159 preschoolers with RPF/RVF (male RPF group, n = 95; female RPF group, n = 26; RVF, n = 38) and 128 normal control preschoolers (control group, n = 128; female control group, n = 35), according to the bowel function score (BFS) obtained through a questionnaire survey, the BFS items in the questionnaire, and the clinical characteristics of patients were compared among groups. The rates of bowel dysfunction (BFS < 17) were 27.2% and 50.0% in the RPF and RVF groups, respectively. Normal rates of BFS items, namely, ability to hold back defecation, feels/reports of the urge to defecate, frequency of defecation, and constipation, in the RPF and RVF groups were significantly lower than those in the control and female control groups (all p < 0.05). After subgroup analysis among the male RPF, female RPF, and RVF groups, higher rates of normal bowel function and ability to hold back defecation were found in the male RPF group than in the female RPF and RVF groups (p < 0.05). Normal rates of feels/reports of the urge to defecate were higher in the male and female RPF groups than in the RVF group (all p < 0.05). The rate of never soiling in the male RPF group was significantly higher than that in the RVF group (p < 0.05).  Conclusions: In patients with RPF/RVF, bowel dysfunction is still prevalent, characterized by inadequate ability to hold back defecation, inability to feel/report the urge to defecate, soil, less frequent defecation, and constipation. However, male RPF patients had better overall bowel function than female RPF or RVF patients, including more adequate ability to hold back defecation and feels/reports of the urge to defecate and slighter soiling, which may be linked to early age at surgery, low occurrences of low sacral ratio, and tethered cord in male RPF.  Trial registration: This study was retrospectively registered in ClinicalTrials.gov on 09/01/2023 (NCT05716230). What is Known: • Rectoperineal and rectovestibular fistula (RPF/RVF) of the anorectal malformation (ARM) type has a good prognosis but may cause bowel dysfunction, especially constipation. • Bowel dysfunction at preschool age may lead to social and psychological disorders that undermine the quality of life in adolescence and adulthood. What is New: • Bowel function in preschoolers with RPF/RVF was deeply evaluated in a relatively large number of patients and normal control children. • Features of bowel dysfunction in RPF/RVF preschoolers across type and gender differences were identified in this study.