The human colon/rectum have bacterial density approaching 1012 bacteria/mL of rectal mucosa.1 Prior to the emergence of antibiotics into surgical practice, elective colorectal surgery had a surgical site infection (SSI) rate greater than 80%.2 Even with preoperative systemic antibiotics alone, elective colorectal surgical infection rates have exceeded 20%.3 These high infection rates have led to multiple investigations of mechanical bowel preparation (MBP) with poorly absorbed oral antibiotics before the operation to reduce microbial colonization and subsequent infections following elective colorectal surgery. Controversy continues about both the MBP and the use of oral antibiotics, with different organizations making contrasting and conflicting recommendations.