A patient with a non-obstructing carcinoma of the sigmoid colon is being prepared for elective resection. To minimize the risk of postoperative infectious complications, your planning should include - a- A single preoperative parenteral dose of antibiotic effective against aerobes and anaerobes b- Avoidance of oral antibiotics to prevent emergence of Clostridium difficile c- Postoperative administration for 2 to 4 days of parenteral antibiotics effective against aerobes and anaerobes d- Postoperative administration for 5 to 7 days of parenteral antibiotics effective against aerobes and anaerobes e- Operative time less than 5 h Answer: c- Postoperative administration for 2 to 4 days of parenteral antibiotics effective against aerobes and anaerobes. (Schwartz, 7/e, pp 143-149) Many clinical and experimental studies have looked at the optimum bowel preparation and preoperative regimen for elective colonic surgery to reduce the postoperative infectious complications of wound infection, intraabdominal abscess and anastomotic leakage. Currently, a postoperative rate of wound infection of only 5% can be attained by combining mechanical cleansing, oral antibiotics, and perioperative parenteral antibiotics. The type of mechanical cleansing does not matter as long as it is effective. Preoperative oral antibiotics may be administered one or more days prior to surgery and should cover aerobes and anaerobes (e.g. neomycin - erythromycin). Parenteral antibiotics effective against aerobes and anaerobes (e.g. cefoxitin) should be administered on call to the operating room as a single dose and no more than 24 h postoperatively. Both antibiotic regimens yield maximum prophylaxis without fostering resistant transformation of microbes. Procedures that require operative time greater than 3 h or that involve the extra-peritoneal rectum are associated with an increased risk of infectious complications.