Combined Mechanical and Oral Antibiotic Bowel Preparation Reduces Incisional Surgical Site Infection and Anastomotic Leak Rates After Elective Colorectal Resection: An Analysis of Colectomy-Targeted ACS NSQIP

Ann Surg. 2015 Aug;262(2):331-7. doi: 10.1097/SLA.0000000000001041.


Objective: To determine the association between preoperative bowel preparation and 30-day outcomes after elective colorectal resection.

Methods: Patients from the 2012 Colectomy-Targeted American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database who underwent elective colorectal resection were included for analysis and assigned to 1 of 4 groups based on the type of preoperative preparation they received [combined mechanical and oral antibiotic preparation (OAP), mechanical preparation only, OAP only, or no preoperative bowel preparation]. The association between preoperative bowel preparation status and 30-day postoperative outcomes was assessed using multivariate regression analysis to adjust for a robust array of patient- and procedure-related factors.

Results: A total of 4999 patients were included for this study [1494 received (29.9%) combined mechanical and OAP, 2322 (46.5%) received mechanical preparation only, 91 (1.8%) received OAP only, and 1092 (21.8%) received no preoperative preparation]. Compared to patients receiving no preoperative preparation, patients who received combined preparation demonstrated a lower 30-day incidence of postoperative incisional surgical site infection (3.2% vs 9.0%, P < 0.001), anastomotic leakage (2.8% vs 5.7%, P = 0.001), and procedure-related hospital readmission (5.5% vs 8.0%, P = 0.03). The outcomes of patients who received either mechanical or OAP alone did not differ significantly from those who received no preparation.

Conclusions: Combined bowel preparation with mechanical cleansing and oral antibiotics results in a significantly lower incidence of incisional surgical site infection, anastomotic leakage, and hospital readmission when compared to no preoperative bowel preparation.

MeSH terms

  • Administration, Oral
  • Aged
  • Anastomotic Leak / epidemiology
  • Anastomotic Leak / prevention & control*
  • Anti-Bacterial Agents / administration & dosage*
  • Antibiotic Prophylaxis
  • Colectomy / adverse effects*
  • Colonic Diseases / complications
  • Colonic Diseases / pathology
  • Colonic Diseases / surgery*
  • Elective Surgical Procedures / adverse effects
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Preoperative Care*
  • Retrospective Studies
  • Surgical Wound Infection / epidemiology
  • Surgical Wound Infection / prevention & control*


  • Anti-Bacterial Agents