Botulinum toxin A injection before hemorrhoid surgery to reduce postoperative pain

Effect of Internal Anal Sphincter Botulinum Toxin A Injection 7 Days Before Hemorrhoidectomy on Postoperative Pain: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Phase 2 Interventional Lomonosov Moscow State University Medical Research and Educational Center · NCT07399860

This study will see if injecting botulinum toxin A into the internal anal sphincter a week before hemorrhoidectomy reduces post-operative pain for adults with grade III–IV hemorrhoids.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment292 (estimated)
Ages18 Years and up
SexAll
SponsorLomonosov Moscow State University Medical Research and Educational Center Academic / other
Locations1 site (Moscow, Moscow)
Trial IDNCT07399860 on ClinicalTrials.gov

What this trial studies

This randomized, double-blind, placebo-controlled Phase 2 trial gives adult patients with symptomatic grade III–IV hemorrhoids either botulinum toxin A or saline injected into the internal anal sphincter seven days before excisional hemorrhoidectomy. Injections are performed in four quadrants using a standardized technique and both patients and surgeons are blinded to allocation. All participants undergo open or closed hemorrhoidectomy with standardized perioperative care, and postoperative pain is measured with a visual analogue scale during the first seven days. Secondary outcomes include analgesic use, complications, length of stay, transient fecal incontinence, time to first bowel movement, readmissions, and patient satisfaction within 30 days.

Who should consider this trial

Good fit: Adults aged 18 or older with symptomatic grade III–IV hemorrhoids scheduled for open (Milligan-Morgan) or closed (Ferguson) excisional hemorrhoidectomy and without contraindications to botulinum toxin are ideal candidates.

Not a fit: Patients with prior anal sphincter surgery, baseline fecal incontinence, neuromuscular junction disorders, active anorectal infection or inflammatory bowel disease in the active phase, pregnancy or breastfeeding, or those who cannot safely stop anticoagulation are unlikely to receive benefit and are excluded.

Why it matters

Potential benefit: If successful, preoperative botulinum toxin A could reduce postoperative pain, lower analgesic needs, and speed recovery after hemorrhoidectomy.

How similar studies have performed: Botulinum toxin A has proven effective for anal sphincter spasm and chronic anal fissure, but its preoperative use to reduce pain after hemorrhoidectomy is less well established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adults ≥18 years, male and female
* Symptomatic grade III-IV hemorrhoidal disease (Goligher), refractory to conservative treatment
* Scheduled for open (Milligan-Morgan) or closed (Ferguson) hemorrhoidectomy

Exclusion Criteria:

* Known hypersensitivity to botulinum toxin A, human albumin, or local anesthetics.
* Neuromuscular junction disorders (e.g., myasthenia gravis, Lambert-Eaton syndrome).
* Use of aminoglycosides or other agents interfering with neuromuscular transmission within 14 days.
* Coagulopathy or ongoing anticoagulant therapy not suitable for perioperative interruption.
* Active anorectal infection, fissure, abscess, or inflammatory bowel disease in the active phase.
* Previous anal sphincter surgery or baseline fecal incontinence.
* Pregnancy or breastfeeding.
* ASA ≥ III or significant systemic disease compromising anesthesia or wound healing.
* Participation in another interventional clinical trial within 30 days.

Where this trial is running

Moscow, Moscow

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HemorrhoidsPostoperative PainHemorrhoidectomyBotulinum toxinPostoperative painAnal sphincter spasm
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.