This was a double-blind randomized trial. Patients between 4 and 16 years old were included in the study if they had failed to respond to laxative treatment and anal dilatation for chronic idiopathic constipation. All study patients had anorectal manometry and anal endosonography under ketamine anesthesia. Outcome was measured using a validated symptom severity (SS) scoring system, with scores ranging from 0 to 65.
Of 42 children, 21 were randomized to the botulinum group and 21 were randomized to the myectomy group. At the 3-month follow-up, the median preoperative SS score improved from 34 (range = 19-47) to 20 (range = 2-43) in the botulinum group (P < .001) and from 31 (range = 18-49) to 19 (range = 3-47) in the myectomy group (P < .002). At the 12-month follow-up, the scores were 19 (range = 0-45) and 14.5 (range = 0-41) for the botulinum group and the myectomy group, respectively (P < .0001). There was no complication in both groups.
Botulinum toxin is equally effective as and less invasive than myectomy of the IAS for chronic idiopathic constipation and fecal incontinence in children.