A Phase 2 interventional study of Botulinum toxin type A and Saline (0.9% NaCl) in Hemorrhoids and Postoperative Pain, sponsored by Lomonosov Moscow State University Medical Research and Educational Center. Recruiting at 1 site in Russia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-10.
Sponsored by Lomonosov Moscow State University Medical Research and Educational Center · Phase 2, Interventional, and Prevention
Hemorrhoidectomy is an effective surgical treatment for advanced hemorrhoidal disease but is often associated with significant postoperative pain, which may delay recovery. One of the main contributors to pain after hemorrhoidectomy is spasm and increased tone of the internal anal sphincter.
This randomized, double-blind, placebo-controlled clinical trial evaluates whether preoperative injection of botulinum toxin type A into the internal anal sphincter, performed seven days before hemorrhoidectomy, can reduce postoperative pain compared with placebo. Adult patients with grade III-IV hemorrhoids scheduled for excisional hemorrhoidectomy will be randomized to receive either botulinum toxin A or saline injection prior to surgery.
Postoperative pain intensity, analgesic consumption, complications, functional outcomes, and patient satisfaction will be assessed during the first 30 days after surgery.
This multicenter, randomized, double-blind, placebo-controlled trial is designed to investigate the effect of preoperative botulinum toxin type A injection into the internal anal sphincter on postoperative pain following excisional hemorrhoidectomy.
Eligible adult patients with symptomatic grade III-IV hemorrhoids will be randomized in a 1:1 ratio to receive either botulinum toxin type A or placebo injection seven days prior to surgery. Botulinum toxin A will be injected into the internal anal sphincter in four quadrants using a standardized technique, while the control group will receive an identical volume of normal saline. Both patients and surgeons performing hemorrhoidectomy, as well as outcome assessors, will be blinded to treatment allocation.
All participants will subsequently undergo open or closed hemorrhoidectomy using standardized surgical and perioperative care protocols. Postoperative pain will be assessed using a visual analogue scale during the first seven postoperative days. Secondary outcomes include analgesic consumption, postoperative complications, length of hospital stay, transient fecal incontinence, time to first bowel movement, readmissions, and patient-reported satisfaction within 30 days after surgery.
The study aims to determine whether preoperative chemical sphincter relaxation with botulinum toxin A can improve postoperative recovery and reduce pain following hemorrhoidectomy.
238 studies on the registry are indexed under Hemorrhoids; 73 are open to participants now.
This study's planned enrollment of 292 is above the median of 100 across 183 interventional studies indexed under Hemorrhoids.
Browse Hemorrhoids studies →Lomonosov Moscow State University Medical Research and Educational Center is the lead sponsor of 6 studies on the registry; 3 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive a preoperative injection of botulinum toxin type A into the internal anal sphincter seven days prior to excisional hemorrhoidectomy, in addition to standard surgical treatment.
Drug: Botulinum toxin type A
Participants receive a preoperative injection of normal saline into the internal anal sphincter seven days prior to excisional hemorrhoidectomy, in addition to standard surgical treatment.
Drug: Saline (0.9% NaCl)
Participants receive a single preoperative injection of botulinum toxin type A into the internal anal sphincter. The injection is administered seven days prior to excisional hemorrhoidectomy. Botulinum toxin type A is injected in divided doses at predefined points of the internal anal sphincter using standard technique. The intervention is performed once and no repeat injections are planned.
Also known as: botox, BTX-A
Participants receive a single preoperative injection of normal saline into the internal anal sphincter. The injection is administered seven days prior to excisional hemorrhoidectomy. Normal saline is injected in divided doses at the same predefined points and using the same technique and injection volume as in the experimental group. The intervention is performed once, with no repeat injections planned.
Postoperative Pain Intensity Within the First 7 Days After Hemorrhoidectomy
Postoperative pain intensity assessed using a 100-mm visual analogue scale (VAS). Daily pain scores are recorded and used to calculate the area under the curve (AUC) over postoperative days 1-7 for comparison between study groups.
Time frame: Postoperative days 1-7
Total opioid consumption within 72 hours postoperatively
Total postoperative opioid consumption expressed in morphine equivalents (mg) measured within the first 72 hours after surgery. Opioid use is recorded and compared between the botulinum toxin type A group and the placebo group.
Time frame: Within 72 hours after surgery (postoperative hours 0-72)
Length of hospital stay
Length of postoperative hospital stay measured in days, calculated from the day of surgery to the day of hospital discharge, and compared between the botulinum toxin type A group and the placebo group.
Time frame: From day of surgery until hospital discharge (up to 30 days postoperatively)
Incidence of postoperative complications within 30 days
Incidence of postoperative complications occurring within 30 days after surgery, classified according to the Clavien-Dindo classification, and compared between the botulinum toxin type A group and the placebo group.
Time frame: Within 30 days after surgery
Transient fecal incontinence rates assessed by Wexner score
Transient fecal incontinence assessed using the Wexner score to evaluate severity and frequency of symptoms, and compared between the botulinum toxin type A group and the placebo group.
Time frame: Postoperative days 14 and 30
Readmission or unplanned medical visits within 30 days
Hospital readmission or unplanned medical visits occurring within 30 days after surgery, compared between the botulinum toxin type A group and the placebo group.
Time frame: Within 30 days postoperatively
Pain during defecation assessed by VAS
Pain intensity during defecation assessed using the Visual Analog Scale (VAS) and compared between the botulinum toxin type A group and the placebo group.
Time frame: Postoperative days 1, 3, and 7
Time to first bowel movement
Time to first bowel movement measured in hours and compared between the botulinum toxin type A group and the placebo group.
Time frame: From day of surgery until first bowel movement (up to hospital discharge, maximum 7 days)
Patient satisfaction score
Patient satisfaction assessed using a numeric rating scale from 0 to 10, where higher scores indicate greater satisfaction. Scores are compared between the botulinum toxin type A group and the placebo group.
Time frame: Postoperative day 30
Plan to share: No — Individual participant data will not be shared due to institutional and ethical restrictions and because no data-sharing plan is specified in the study protocol.
Started Feb 2026 (actual). Primary completion is estimated for Jan 2027, 11 months after the start.
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Studies of the drug tested here: Botulinum toxin type A
Lomonosov Moscow State University Medical Research and Educational Center