Overview
Excisional haemorrhoidectomy (Milligan-Morgan technique and variants) is frequently underestimated in terms of postoperative pain severity — published data show pain intensity and opioid demand comparable to major surgery despite the procedure's relatively short duration and small wound size. This reflects the extremely high sensory nerve density of the anal canal and perianal skin, combined with sphincter spasm contributing to the pain experience.
PROSPECT 2025 summary (updating Sammour et al. 2017): Effective interventions include paracetamol + NSAID/COX-2, systemic steroids, pudendal nerve block, topical metronidazole, topical diltiazem, topical sucralfate, topical glyceryl trinitrate (GTN), and botulinum toxin injection. A major shift from the prior guideline: oral metronidazole is now abandoned in favour of topical metronidazole — reflecting accumulated evidence favouring the topical route. Perianal local infiltration is no longer recommended (evidence invalidated); pudendal block remains supported.
Analgesic Pathway
- Paracetamol 1g PO
- NSAID/COX-2 PO
- Laxative — start pre-op or immediately post-op
- Bilateral pudendal nerve block — recommended for all patients
- Systemic steroid (e.g. dexamethasone) IV
- Botulinum toxin IM injection — emerging adjunct
- Closed haemorrhoidectomy or open with electrocoagulation of pedicle (surgical technique)
- Perianal local infiltration alone — evidence invalidated; use pudendal block instead
- Paracetamol 1g QDS regular
- NSAID/COX-2 regular ≤5 days
- Topical metronidazole — applied to wound
- Topical diltiazem, sucralfate, or GTN — alternative/adjunct topical options
- Laxatives — essential, continue regularly
- Opioid PRN rescue
✓ Recommended | ◎ Optional/conditional | ✗ No longer recommended. Based on PROSPECT 2025 update.
Systemic Analgesia
| Agent | Dose | Route | Frequency | Notes |
|---|---|---|---|---|
| Paracetamol | 1 g | IV/PO | QDS | Regular throughout |
| Celecoxib | 200 mg | PO | BD | COX-2 preferred; ≤5 days |
| Ibuprofen | 400 mg | PO | TDS | Non-selective alternative |
| Dexamethasone | 8 mg | IV | Single intraop | Systemic steroid — independently improves pain relief |
| Laxative (e.g. lactulose/senna) | Standard dose | PO | Regular | Essential — prevents straining-related pain and wound trauma; Grade A evidence |
| Oxycodone | 5–10 mg | PO PRN | 4–6h | Rescue; given the severity of pain, do not under-prescribe |
Laxatives are not optional. Avoiding constipation and straining is essential both for comfort and to prevent mechanical disruption of the surgical site. This is one of the most consistently graded (Grade A) recommendations across successive PROSPECT haemorrhoidectomy reviews.
Pudendal Nerve Block
Bilateral pudendal nerve block is recommended for all patients undergoing haemorrhoid surgery, regardless of whether general or regional anaesthesia is also used. A dedicated systematic review and meta-analysis confirmed its analgesic effect. This is a notable upgrade in confidence compared to earlier guidance, which had been more equivocal between pudendal block and simple perianal infiltration.
Anatomy & Technique Summary
The pudendal nerve (S2–S4) can be blocked via a transperineal or transvaginal/transrectal approach, targeting the nerve as it passes near the ischial spine and through Alcock's canal (pudendal canal). Ultrasound-guided transperineal approach is increasingly preferred over blind/landmark technique, improving accuracy and reducing the volume of LA required.
Dosing
| Agent | Concentration | Volume (per side) | Duration |
|---|---|---|---|
| Bupivacaine | 0.25–0.5% | 10 mL | 12–18 h |
| Ropivacaine | 0.5% | 10 mL | 10–16 h |
Bilateral block — calculate total dose for both sides. Performed by the surgeon or anaesthetist depending on local practice and technique availability.
Topical Therapy — Key Guideline Update
The most significant change in the 2025 update: Oral metronidazole, previously recommended, has been abandoned in favour of topical metronidazole. A meta-analysis pooling two trials demonstrated a reduction in pain score of more than one unit, sustained to postoperative day 14, with topical application. Direct oral-versus-topical comparisons also favoured the topical route in two of three trials.
Topical Options — All Independently Effective
| Agent | Mechanism (proposed) | Application |
|---|---|---|
| Topical metronidazole | Local anti-inflammatory/antimicrobial effect at wound | Applied to surgical site, per product instructions, typically for 1–2 weeks postop |
| Topical diltiazem | Calcium-channel blocker — reduces internal sphincter spasm/pressure | Applied to anal area, several times daily |
| Topical sucralfate | Mucosal protective/wound-healing effect | Applied topically to wound |
| Topical glyceryl trinitrate (GTN) | Smooth muscle relaxant — reduces sphincter spasm | Applied to anal area; headache is a recognised side effect, counsel patients |
These topical agents are not mutually exclusive — clinicians may select based on local availability, cost, and patient tolerance (e.g. GTN-associated headache may make diltiazem or sucralfate preferable for some patients).
Botulinum Toxin
Intramuscular botulinum toxin injection (into the internal anal sphincter) is a newer recommended adjunct in the 2025 update, working on the principle of reducing sphincter spasm — a significant contributor to post-haemorrhoidectomy pain. This reflects accumulating evidence since the prior guideline and represents one of the more novel additions to the recommended armamentarium.
Surgical Technique
PROSPECT notes that the choice of haemorrhoidectomy technique is largely left to surgeon discretion based on experience, haemorrhoid type, and recurrence risk — but offers some pain-specific guidance:
| Technique | PROSPECT position | Notes |
|---|---|---|
| Closed haemorrhoidectomy | Recommended (as primary procedure option) | Wound closed after excision — generally favourable pain profile |
| Open haemorrhoidectomy with electrocoagulation | Recommended (alternative primary procedure) | Pedicle electrocoagulation specifically — open wound left to heal |
| Lateral sphincterotomy (adjunct) | Not formally recommended despite new evidence | Some evidence of pain reduction, but safety/continence concerns limit recommendation |
| Mechanical bowel preparation | Not recommended | Grade A — no difference in pain demonstrated |
Not Recommended
Superseded by topical metronidazole in the 2025 update — see dedicated section above.
Contemporary publications invalidate the prior recommendation for simple perianal infiltration as a standalone technique — pudendal nerve block is the now-preferred regional approach.
Grade A evidence shows no difference in postoperative pain with mechanical bowel prep — not recommended for this purpose.
Despite extended analgesic duration demonstrated in some studies, liposomal bupivacaine cannot yet be recommended due to study designs that did not adequately incorporate other established multimodal analgesic techniques as comparators.
Practical Analgesic Protocol
Suggested protocol for closed excisional haemorrhoidectomy:
References
- PROSPECT guideline for haemorrhoid surgery: A systematic review and procedure-specific postoperative pain management recommendations. Eur J Anaesthesiol Intensive Care. 2025. PMID 39917290 ↗
- Sammour T, Barazanchi AWH, Hill AG; PROSPECT Working Group. Evidence-Based Management of Pain After Excisional Haemorrhoidectomy Surgery: A PROSPECT Review Update. World J Surg. 2017;41:603–614. PMID 27766395 ↗
- Lyons NJR, Cornille JB, Pathak S, et al. Systematic review and meta-analysis of the role of metronidazole in posthaemorrhoidectomy pain relief. Colorectal Dis. 2017;19:803–811.
- Mongelli F, Treglia G, La Regina D, et al. Pudendal nerve block in hemorrhoid surgery: a systematic review and meta-analysis. Dis Colon Rectum. 2021;64:617–631.
- Medina-Gallardo A, et al. Pudendal Nerve Block for Hemorrhoidectomy. ClinicalTrials.gov protocol ↗