Infectious complications of colorectal surgery include wound infection, intra-abdominal or pelvic abscesses, and anastomotic leak. They are mainly caused by endogenous colonic cultures. It seems logical that reducing faecal load and the bacterial count in the intestinal lumen should reduce the rate of infections. Bowel preparation before surgery of the colon and rectum consists of mechanical bowel cleaning from residual stool mass and administration of pre-operative intravenous antibiotics. The essential aims are: comfort, assurance and clean environment in the operative field during surgery, reduction of intestinal flora and decrease in the rate of post-operative infectious events. When the colon is evacuated of stool mass, the amount of bacteria is decreased and mechanical disruption of the anastomosis by shaped, dense passing stool is possibly prevented. Each of the surgical centres usually uses their own methods of effective bowel preparation that have been tested over many years.
Mechanical bowel preparation is performed either by oral ingestion of cathartic agents or by enema irrigations. Historically, castor oil, anthroquinolones such as senna, diphenylmethanes such as bisacodyl, and salts such as sodium picosulphate and magnesium citrate in combination with a low residue diet and mannitol as an osmotic agent were used. At present, polyethylene glycol and sodium phosphate are most common. Polyethylene glycol provides a good quality of bowel cleansing from stool mass [1,2]; it is popular and has well proven efficacy [3-5]. Intolerance resulting from a necessarily large volume of oral water intake (41) may appear occasionally in a group of patients. The symptoms include nausea, discomfort, vomiting, abdominal pain and distension [6, 7]. Sodium phosphate is equally effective with the benefit of no adverse events [7, 8], but causes a huge electrolyte imbalance, sodium phosphate should not be used in patients with chronic renal failure, cirrhosis of the liver, advanced heart failure and in patients with symptoms of ascites . Patients tolerate sodium phosphate better but polyethylene glycol was proved to be safer.
During recent years a few studies have shown that colorectal surgery with no mechanical bowel preparation is equally safe and is not associated with higher rates of post-operative adverse events (wound infection, intra-abdominal abscesses, anastomotic leak) [10-13].
The Author uses mechanical bowel preparation with polyethylene glycol before each rectal resection. Despite many studies proving no benefits of bowel preparation, mechanical cleaning of the bowel makes the operation more comfortable for the surgeon, particularly during anastomosis formation. In connection with some unfavourable aspects resulting from mechanical bowel preparation, many surgeons asked if there is a need for pre-operative preparation.
In the past, bowel preparation consisted of administration of non-absorbable antibiotics to reduce the growth of endogenous colonic bacterial culture. For some years information referring to the efficacy of pre-operative bowel preparation has been inconsistent. Some studies demonstrated benefits of a pre-operative neomycin and erythromycin administered in combination, whereas several papers found them to have no effect [14-17]. Nowadays the application of those antibiotics has been given up.
Prophylactic use of pre-operative intravenous antibiotics is a standard procedure in all colorectal surgery. The efficacy of antibiotic infusion (most often second generation of cephalosporins and metronidazole) pre-operatively is well documented
. Unfavourable aspects of prophylactic use of antibiotics are the high costs of the application, the selection of severe and resistant bacterial cultures and also the risk of toxic colitis in the course of a Clostridium difficile infection .
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