The aim of this study was to assess recent literature regarding bowel preparation for colonoscopy and surgery.The study was conducted by an Index Medicus English-language search of articles relevant to both oral mechanical and parenteral and oral antibiotic preparation for elective colorectal surgery and mechanical bowel preparation for colonoscopy. The study period was from 1975 to 2000. In addition, studies of elective colorectal surgery without mechanical bowel preparation were also considered.Although several recent prospective, randomized trials have suggested that elective colorectal surgery can be safely performed without any mechanical bowel preparation, mechanical bowel preparation remains the standard of care, at least in North America at the present time. A recent survey of the members of The American Society of Colon and Rectal Surgeons revealed that the majority currently use sodium phosphate for bowel preparation and use a dual oral antibiotic regimen before elective colorectal surgery, combined with two doses of parenteral antibiotics. Although some of the use patterns are based on prospective, randomized study, others seem founded strictly on habit and theory.The current methods of bowel cleansing for both colonoscopy and surgery include sodium phosphate and polyethylene glycol; colorectal surgeons practicing in North America currently prefer sodium phosphate. Additional preparation for colorectal surgery includes perioperative parenteral antibiotics and, to a slightly lesser degree, preoperative oral antibiotic preparation. Although some recent prospective, randomized studies have suggested that omission of mechanical bowel preparation for elective colorectal surgery is not only feasible but potentially preferable, caution is recommended before routinely omitting these widely practiced measures, because data to support such routine omission are limited.