UNASSIGNED: To assess the effect of megarectum on postoperative defecation of female patients with congenital rectovestibular fistula or rectoperineal fistula.
UNASSIGNED: From March 2013 to February 2021, 74 female patients with congenital rectovestibular fistula or rectoperineal fistula were treated. The age of patients ranged from 3 months to 1 year. Barium enema and spinal cord MRI were performed in all children. 4 patients were removed from the study because of spinal cord and sacral agenesis. Finally, 70 patients underwent one-stage anterior sagittal anorectoplasty (ASARP). Anal endoscopy and anorectal pressure measurement were performed 1 year after surgery. All patients were divided into two groups depending on the presence of megarectum (+) and (-) and observed for constipation and anal sphincter function.
UNASSIGNED: 16 patients (4 months to 1 year) were complicated with megarectum, and 5 patients (3 months to 9 months) were without megarectum. The incision infection was seen in 3 patients. All patients were followed up for 1 year to 5 years. Fecal soiling was seen in 2 patients and constipation in 14 patients. Among 16 patients with megarectum, soiling was seen in 1 patient and the constipation in 12 patients. Among 54 patients without megarectum, soiling was seen in 1 patient and constipation in 2 patients. There was a significant difference in the incidence of postoperative constipation between the two groups (megarectum (+) 75% vs. megarectum (-) 3.7% (P < 0.05)). However, there was no significant difference in the score of anal sphincters between the two groups (P < 0.05). And there was no significant difference in anal resting pressure (P = 0.49) and length of anal high pressure area (P = 0.76). 7 patients with constipation and megarectum acquired normal anal function after the dilated rectum was resected.
UNASSIGNED: Megarectum increases the possibility of difficult postoperative defecation in the patients with congenital rectovestibular fistula or rectoperineal fistula. However, constipation was not associated with ASARP postoperative effects on sphincter function. Resection of megarectum is helpful to the improvement of constipation.

OBJECTIVE: This study aims to discuss the treatment of congenital recto-vestibular fistula and recto-perineal fistula, and the effect of the megarectum on defecation.
BACKGROUND: Congenital recto-vestibular fistula or recto-perineal fistula is the most common type of anorectal malformation, and surgical methods include posterior sagittal anorectoplasty, anterior sagittal anorectoplasty, and mid-sagittal anorectoplasty, which can be performed at stage one or stage two after the ostomy. In the later stages of a recto-vestibular fistula, constipation is a common complication. Rectal dilatation is frequently associated with constipation, and the effect of rectal dilatation on defecation should be discussed for patients with congenital recto-vestibular or recto-perineal fistula who had rectal dilatation prior to surgery. Rectal dilatation may be one of the causes of constipation for congenital recto-vestibular fistula and recto-perineal fistula.
METHODS: The patients in this study were 67 children with congenital recto-vestibular fistula or recto-perineal fistula treated in our hospital from March 2013 to February 2017. All patients underwent an MRI of the spine and a barium enema. Six patients with myelodysplasia and sacral agenesis were excluded from this study. There were 18 patients with rectal dilatation (ages: 4-month-old to 1 year old, male: 3, female: 15). Seven of them had anterior sagittal anorectoplasty (group A), and 11 had anorectoplasty with dilated rectum resection (group B). Forty-three patients (ages: 3- to 10 months old, male: 6; female: 37) without a dilated rectum underwent anterior sagittal anorectoplasty (group C).
RESULTS: All patients were followed up for 1 year to 5 years. Among the 50 patients who had undergone an anoplasty, 5 out of 7 patients with rectal dilatation developed post-operative constipation, and 3 of them had normal defecation after the second resection of the dilated rectum. Only two out of 43 patients without rectal dilatation developed post-operative constipation. One out of 11 patients with rectal dilatation who underwent anoplasty and resection of the dilated rectum developed post-operative constipation.
CONCLUSIONS: Patients with congenital recto-vestibular fistula or recto-perineal fistula complicated by rectal dilatation are more susceptible to post-operative constipation. Resection of the dilated rectum at the same time can reduce the incidence rate of constipation. A barium enema should be performed pre-operatively for patients with congenital recto-vestibular fistula or recto-perineal fistula. If the dilated rectum is found, it can be resected at the same time.