Whole bowel irrigation (WBI) was used in 50 children aged 16 months to 14 years in preparation for surgery (n=30) and colonscopy (n=20). The patients were divided into three groups according to age: group A, 12 to 36 months; group B, 3 to 6 years; and group C, 6 to 14 years. A hydroelectrolytic solution (Na 150 mEq/L, K 30 mEq/L, Cl 130 mEq/L, HCO 3 50 mEq/L) was administered to all the groups at a variable rate established according to tolerance, weight, and age. Neomycin (1 g) and erythromycin (50 mg/kg) were administered in the last liter of the solution of the patients being prepared for colorectal surgery. Vital signs (heartbeat, arterial tension, and central venous pressure) and blood parameters (Na, K, HCO 3, pH, and Hct) were assessed before and after irrigation and remained stable in all the groups. The rate of administration of the solution was best tolerated in each group as follows: group A, 75 mL/kg/h; group B, 60 mL/kg/h; and group C, 45 mL/kg/h. Colonic preparation was satisfactory in 49 of the 50 cases. Postoperative infectious complications were reduced to 3.3%. WBI in pediatric patients is a fast, simple, and well-tolerated method that gest a colon in excellent condition for surgery and colonoscopy exploration and considerably decreases the number of postoperative complications.