Bowel Preparation and Oral Antibiotic Agents for Selective Decontamination in Colorectal Surgery: Current Practice, Perspectives, and Trends in Australia and New Zealand, 2019–2020

Background: There has been much debate as to the importance of mechanical bowel preparation (MBP) and oral antibiotic agents (OAB) prior to elective colorectal surgery over the past two decades. There is no consensus between international guidelines. Methods: The Australia and New Zealand Mechanical Bowel Preparation and Oral Antibiotics (ANZ-MBP-OAB) questionnaire was distributed to colorectal surgeons after institutional board approval assessing specialist attitudes toward 18 enhanced recovery after surgery (ERAS) interventions. Data were analyzed using a rating scale and graded response model in item response theory (IRT) on Stata MP, version 15 (StataCorp LP, College Station, TX). Specialist attitudes toward the effectiveness of MBP and OAB strategies in providing better short-term outcomes was ranked alongside other ERAS interventions. This was followed by specific questions examining current practice, perspectives, and trends. Results: Ninety-five of 300 (31.7%) colorectal surgeons in Australia and New Zealand participated in the survey. Statistical modeling was achieved in 13 ERAS interventions. Compared with other ERAS interventions, the use of MBP with OAB and MBP alone ranked nine of 13 and 10 of 13, respectively, in order of effectiveness in providing better short-term outcomes after colorectal surgery. Oral antibiotic agents alone was not considered effective. Mechanical bowel preparation with OAB was considered to be the best strategy in both colon (37%) and rectal surgery (48%) but current practice varied substantially from perspective. Mechanical bowel preparation alone was strongly favored in rectal surgery (81%) with only 14% using MBP with OAB. In colon surgery, only 10% used MBP with OAB, with MBP alone (45%) and no preparation (45%) being equally the most commonly used strategies. Conclusions: Among Australian and New Zealand colorectal surgeons, MBP with OAB was considered the best bowel preparation strategy. However, despite an awareness of its benefits, MBP with OAB has yet to be widely adopted into clinical practice or guidelines in Australia and New Zealand.