Mechanical bowel preparation combined with oral antibiotics reduces infectious complications and anastomotic leak in elective colorectal surgery: a pooled-analysis with trial sequential analysis

Int J Colorectal Dis. 2023 Jan 9;38(1):5. doi: 10.1007/s00384-022-04302-8.


Objective: A pooled analysis combined with trial sequential analysis (TSA) was conducted in order to explore the effect of mechanical bowel preparation (MBP) combined with oral antibiotic bowel decontamination (OAB) versus MBP alone on patients who have undergone colorectal resection.

Methods: Comprehensive and systematic searches of PubMed, Embase, Cochrane Library, Web of Knowledge, and Clinical databases were conducted. The quality of literature was evaluated using Cochrane risk bias assessment tool as well as Newcastle-Ottawa Scale (NOS) score. A pooled analysis of randomized controlled trials (RCTs) and prospective studies was performed comparing patients who underwent colorectal resection and received MBP plus OAB or MBP alone. The outcome endpoints were the incidence of anastomotic leak (AL) and surgical site infection (SSI). TSA is a tool used to assess the reliability of currently available evidence to determine further clinical trial validation.

Results: The analysis included a total of 22 studies involving 8852 patients, including 3016 patients in the MBP + OAB group and 4415 patients exposed to MBP alone. The pooled analysis showed that the incidence of postoperative anastomotic leak was significantly lower in the group treated with MBP plus OAB compared with MBP alone (OR = 0.43, 95% CI: 0.23-0.81, P = 0.009, I2 = 73%). The incidence of postoperative surgical site infections was significantly lower in the group exposed to the combination of MBP and OAB compared with MBP alone (OR = 0.38, 95% CI: 0.32-0.46, P < 0.0001, I2 = 24%). The TSA demonstrated significant benefits of MBP plus OAB intervention in terms of AL and SSI.

Conclusion: MBP combined with OAB significantly reduces the incidence of AL and SSI in patients after colorectal resection compared with MBP alone.

Keywords: Anastomotic leak; Colorectal surgery; Mechanical bowel preparation; Oral antibiotics; Surgical site infection.

Publication types

  • Systematic Review

MeSH terms

  • Anastomotic Leak / drug therapy
  • Anastomotic Leak / etiology
  • Anastomotic Leak / prevention & control
  • Anti-Bacterial Agents / therapeutic use
  • Antibiotic Prophylaxis
  • Cathartics
  • Colorectal Neoplasms* / surgery
  • Colorectal Surgery* / adverse effects
  • Elective Surgical Procedures / adverse effects
  • Humans
  • Preoperative Care
  • Randomized Controlled Trials as Topic
  • Surgical Wound Infection / drug therapy
  • Surgical Wound Infection / etiology
  • Surgical Wound Infection / prevention & control


  • Anti-Bacterial Agents
  • Cathartics