Pain after hemorrhoidectomy appears to be multifactorial, depending on individual pain tolerance, mode of anesthesia, postoperative analgesia, and surgical technique.
Spasm of the internal anal sphincter is believed to play an important role in postoperative pain.
A study by Doctors in York, UK, investigated the role of botulinum toxin in reducing pain after Milligan-Morgan hemorrhoidectomy.
50 consecutive patients undergoing hemorrhoidectomy were randomized to receive an internal sphincter injection of 0.4 ml of solution containing either botulinum toxin (20 units Botox) or normal saline.
Pain was assessed by use of daily visual analog scores and analgesia requirements for the first seven days after surgery.
Patients randomized to receive botulinum toxin had lower daily average and maximal pain scores throughout the study period.
| Patients who had botulinum toxin had significantly less pain toward the end of the first week after surgery.”|
|Diseases of the Colon and Rectum|
Pain scores were significantly lower in the botulinum toxin group than in the control group on the 6th and 7th days after surgery.
There was no significant difference in analgesia requirement between the botulinum toxin group and the control group.
The authors of the study conclude: “Those patients who had botulinum toxin had significantly less pain toward the end of the first week after surgery.”
“Reduction in spasm within the internal anal sphincter is the presumed mechanism of action.”