Mechanical and antibacterial bowel preparation in colon and rectal surgery

Colorectal surgery performed prior to 1970 was fraught with postoperative infectious complications which occurred in more than 30-50% of all operations. Diversion of the fecal stream appeared mandatory when operating on an urgent or emergent basis, thereby requiring the performance of multiple, staged operations instead of a single surgery encompassing resection and primary anastomosis as is performed commonly today. Multiple studies conducted in the early 1970s determined that anaerobic colonic microflora were causative agents in postoperative infections in colon and rectal surgery, and these studies initiated the development of effective oral preoperative antibiotic prophylaxis in combination with preoperative mechanical bowel preparation. This dual-tier regimen significantly reduced the incidence of postoperative infectious complications, thus allowing most uncomplicated colon and rectal surgeries to be performed in a single stage without the need for the diversion of the fecal stream and multiple operations. Therefore, a preoperative mechanical and antibacterial bowel regimen serves as the cornerstone of modern elective colorectal surgery, and these regimens now comprise three therapeutic directives. The first step is preoperative mechanical cleansing of the bowel, which is then followed by preoperative oral antibiotic prophylaxis. Finally, perioperative parenteral antibiotics directed against aerobic and anaerobic colonic microflora are utilized.