Can botulinum toxin help in managing children with functional constipation and obstructed defecation?

[BACKGROUND] Functional constipation (FC) is a common pediatric healthcare problem worldwide. Obstructed defection syndrome (ODS) is frequently presented with an inability to coordinate the bowel movement with pelvic floor muscles. Botulinum toxin (BT) intraanal sphincteric injection can improve the obstructed defecation by relaxing the anal sphincter and reducing the required force to propel the stools.

[PURPOSE] This study aimed to compare the changes in Rintala scores (as a mean of assessing defecatory function), in children with FC and ODS, managed by BT injection, bowel management program (BMP), and senna based laxatives (SBL), versus a control group managed by BMP and SBL only.

[METHODS] Prospective randomized controlled study, started at December 2017 on 40 pediatric patients, divided into 2 equal groups (group A: managed by BMP and SBL, group B: like group A with once intraanal sphincteric BT injection) suffering from FC, ODS, with contrast enema showing persistence of ≤90 rectoanal angle (RAA) even with trials of defecation. Patients were excluded if they have neuromuscular abnormalities, hypothyroidism, previous colorectal or anal surgery. Rintala score was assessed before treatment, at 2 months, and 6 months after management.

[RESULTS] The study included 18 females (45%) and 22 males (55%). Group A had equal gender distribution and mean age of 6.9 years, while group B had 12 males with mean age of 7.35 years. The mean follow up period was 11.35 months in group A and 11.6 months in group B. Mean Rintala scores of both groups at initial presentation, 2 months and 6 months follow up were: group A: 9.10, 9.40, 10.90; group B: 9.30, 10.70, 11.05 respectively, and showed no statistically significant difference (p value: 0.884, 0.294, 0.923 respectively). No complications were detected from BT injection like allergic reactions, neuromuscular urinary or lower limbs disturbances.

[CONCLUSION] Intraanal sphincteric injection of botulinum toxin by the mentioned technique and dose, did not result in additional defecatory functional improvement (when assessed by Rintala score) over the routine protocol (using bowel management program and laxatives) of managing functional constipation with obstructed defecation. ANNOUNCEMENT: a preliminary report of this work was presented in the 34th Egyptian pediatric surgery association (EPSA) meeting in Cairo in November 2019.

[TYPE OF STUDY] Treatment/prospective study.

[LEVEL OF EVIDENCE] Level I.