Influence of bifidobacterium on surgical site infection and enterobacterial flora in colorectal cancer surgery

Interventions: polyethylene glycol-electrolyte sodium (2 L)
polyethylene glycol-electrolyte sodium (2 L) oral antibiothics ()Kanamycin, metronidazol)
polyethylene glycol-electrolyte sodium (2 L) oral Bifidobacterium
Primary outcome(s): surgical site infection changes of enterobacterial flora
Study Design: Parallel Randomized