Preoperative Antibiotic Prophylaxis for Hemorrhoidectomy
Preoperative antibiotic prophylaxis is not recommended for routine hemorrhoidectomy, as postoperative surgical site infections are exceedingly rare (1.4% incidence) and antibiotics do not reduce this already low infection rate.
Evidence Against Routine Prophylaxis
The strongest evidence comes from a 2024 randomized clinical trial of 150 patients undergoing Milligan-Morgan hemorrhoidectomy, which demonstrated no efficacy of intravenous prophylactic antibiotics 1. This study compared three groups: no antibiotics, single-dose cefoxitin, and two-dose cefoxitin, finding no significant differences in:
- Pain scores (VAS) on postoperative days 1,3, and 7 1
- Wound edema, bleeding, or urinary retention 1
- White blood cell counts, neutrophil percentages, or C-reactive protein levels 1
A 2014 retrospective study of 852 hemorrhoidectomy patients corroborates these findings, reporting an overall surgical site infection rate of only 1.4% 2. Critically, of the 12 patients who developed infections, 75% had not received antibiotic prophylaxis, but this difference was not statistically significant (p = 0.25) 2. Multivariate regression analysis found no perioperative risk factor associated with increased infection risk 2.
Why Hemorrhoidectomy Differs from Other Procedures
While colorectal surgery guidelines mandate antibiotic prophylaxis (reducing surgical site infections from 39% to 13%), this applies to procedures involving bowel preparation and colonic resection 3. Hemorrhoidectomy is fundamentally different—it is a clean-contaminated perianal procedure without bowel entry, resulting in infection rates already below the 5% threshold that defines clean surgery 2.
General Principles of Antibiotic Prophylaxis (When Indicated)
For procedures where prophylaxis IS indicated, the following principles apply:
- Antibiotics must be administered within 60 minutes before incision 3, 4, 5
- Prophylaxis should be discontinued within 24 hours after surgery 3, 6, 4
- Continuing antibiotics beyond 24 hours increases antibiotic resistance, adverse effects, and healthcare costs without additional benefit 6, 4
Common Pitfalls to Avoid
- Do not prescribe "just in case" antibiotics for routine, uncomplicated hemorrhoidectomy 6
- Do not confuse prophylaxis with therapeutic antibiotics—if a patient develops signs of infection postoperatively (purulent drainage, fever >38.5°C, extensive erythema), therapeutic antibiotics are indicated, but this is treatment, not prophylaxis 7
- Do not extend prophylaxis into the postoperative period based on theoretical concerns; this practice lacks evidence and promotes resistance 3, 4
When Therapeutic Antibiotics ARE Indicated
If postoperative infection develops (rare at 1.4%), therapeutic antibiotics should cover typical skin flora. However, this represents treatment of established infection, not prophylaxis 2.