Macrogol is the international nonproprietary name used for polyethylene glycol (PEG) as a medication ingredient. It is usually followed by a number indicating the average molecular weight, indicating the length of the polymer of the specific molecule in use. Macrogol is used as a laxative to treat constipation in children and adults. It is orally administered, with a resultant bowel movement typically occurring within a few days. A much larger dose of Macrogol is administered to clear the bowels, as preparation prior to a colonoscopy; the onset of the laxative effect is more rapid at this dosage, with onset of action typically occurring within an hour and lingering effects lasting for up to a few days. Small amounts of Macrogol are also occasionally used similarly to baby laxative, as an excipient.