A patient with a nonobstructing carcinoma of the sigmoid colon is being prepared for elective resection. Which of the following reduces the risk of postoperative infectious complications?

The appropriate dosing and timing of antibiotic prophylaxis to prevent surgical site infections in an elective procedure is a single dose, no greater than 1 hour prior to the incision. Additionally, most textbooks recommend use of an oral, nonabsorbable antibiotic regimen effective against aerobes and anaerobes in combination with a mechanical bowel preparation before elective colon resections. There is no evidence to suppo the continuation of antibiotics for more than 24 hours after an elective operation has been completed, and this practice should be avoided to prevent increasing microbial drug resistance. For complex, prolonged procedures, redosing of antibiotics may be appropriate during the procedure based on the drug's halflife. Broad-spectrum antibiotic coverage, including against anaerobic organisms, is required only in cases where such flora are anticipated, such as during colon resections.