Comparison of the Results of Ultrasound-Guided Using Surface Probe and Non-Ultrasound-Guided Botulinum Toxin Injection into the Internal Anal Sphincter in Children with Constipation-Randomized Clinical Trial.

Background: The injection of botulinum toxin (BTX) into the internal anal sphincter (IAS) can temporarily relieve functional bowel obstruction; however, it can be challenging when performed only by touch. Hence, the present study aimed at comparing the results of ultrasound (US)-guided using surface probe and non-US-guided BTX injection into IAS in children with constipation. Materials and Methods: The current single-blind randomized clinical trial was conducted on 40 children with constipation who were divided into two groups. In the first group, US-guided BTX injection into the IAS was performed using a surface probe. In the second group, non-US-guided BTX injection was performed only by touching with the index finger. Then, the recovery of constipation and fecal incontinence was checked in the second week as well as the first and third months after the intervention. Results: The constipation recovery after BTX injection in the US-guided group in the second week (95%) and the first month (95%) was significantly more than its recovery in the non-US-guided group in the second week (70%) and the first month (75%) ( Conclusions: US-guided BTX injection using a superficial probe is effective and safe for constipation recovery.