This study documents the efficacy, safety and patient tolerance of GoLYTELY (Braintree Laboratories, Inc., Braintree, Mass.) an orally administered, nonexplosive, polyethylene glycol-electrolyte lavage solution, in elective colonic surgery. Fifty-three patients admitted for colonic surgery were randomized to either GoLYTELY or a traditional 3-day bowel preparation. Both groups received oral and perioperative antibiotics. Pre- and postpreparation weights, blood chemistries, and hematologic values were obtained. Postpreparation patient tolerance was assessed. During surgery the surgeon scored the bowel for the presence of retained air, fluid, or feces. Standardized semiquantitative aerobic and anaerobic bacterial counts were obtained from sigmoid aspirates. Postoperative infectious complications were recorded. Mechanical preparation with GoLYTELY resulted in a greater feeling of fullness, while the traditional preparation produced more hunger and abdominal cramping. The use of GoLYTELY resulted in better scores of overall quality and bowel appearance, reflecting a greater efficiency with which it removed air, fluid, and feces from the bowel. GoLYTELY also resulted in significantly fewer total aerobic and anaerobic organisms in sigmoid aspirates. This study suggests that GoLYTELY is a safe, well-tolerated, and effective orthograde lavage solution that has significant advantages over other mechanical preparations and should be considered the preparation of choice for elective colonic surgery.