Effect of mechanical bowel preparation on anastomotic integrity following low anterior resection in dogs.

To assess the effect of mechanical bowel preparation on anastomotic integrity after low anterior resection, 36 mongrel dogs were randomized to have low anterior resection with or without mechanical bowel preparation. All dogs received prophylactic antibiotics and anastomotic integrity was assessed on the ninth postoperative day by barium enema, inspection of anastomoses for defects after careful excision at laparotomy, and anastomotic bursting pressures. Bursting pressures were significantly higher (P less than 0.005) in the group with bowel preparation. Anastomotic defects were present in 13 per cent of animals with bowel preparation and 47 per cent without bowel preparation (P = 0.057). Pelvic abscess and death from peritonitis occurred in 6 per cent of the group with bowel preparation and 29 per cent of the unprepared group. Mechanical bowel preparation significantly enhanced anastomotic integrity and reduced complications in this model.