PREOPERATIVE oral antibiotic sterilization of the bowel has been an accepted surgical adjuvant since the introduction of sulfonamides over 25 years ago. Numerous antibiotic regimens have been used to induce local bowel sterilization, both bacteriocidal and bacteriostatic. The sulfonamides, broad spectrum antibiotics, neomycin, neomycinsulfa combinations and most recently, kanamycin sulfate, have all been highly recommended. The common pharmacological denominator of these agents is their poor absorption from the gastrointestinal tract thereby accentuating local antibiosis within the gut lumen with a relatively low blood level. The ideal antibiotic for a bowel preparation should not destroy colonic mucosa, induce systemic toxicity, or cause an overgrowth of pathogens. The wide range of oral antibiotics employed over the years is evidence that the perfect agent has yet to be found. However, in general, intestinal antibiosis appears highly beneficial and most surgeons continue to use antibiotics in their preoperative armamentarium. There is no question that