Whole bowel irrigation is undertaken either by having the patient drink the solution or a nasogastric tube is inserted and the solution is delivered down the tube into the stomach. When administered to adolescents and adults as preparation for surgery, colonoscopy, or another procedure, the solution is usually taken orally, unless oral administration is contraindicated. Orally, the solution may be taken in a wide variety of settings, and is usually taken at a rate of 240 mL (8 oz.) every 10 to 20 minutes. Nasogastrically, the solution is generally administered at a rate of 500 mL/h in children 9 months to 6 years, 1000 mL/h in children 6 to 12 years, and 1500 to 2000 mL/h in adolescents and adults. When used to cleanse the bowels for a procedure, the total volume of solution prescribed is usually 2 to 4 liters, which is often taken at home by the patient.