A polyethylene glycol (PEG) electrolyte lavage solution (PEG-ELS) was originally developed in 1980 by the Fordtran group as isosmotic preparation for minimal water and electrolyte exchange with plasma to ensure safe cleansing of the bowel through a mechanical effect of large-volume lavage. The conventional total dose of 4 L given the day before the procedure is safe and effective and has been the standard cleansing regimen for the last 25 years. To overcome the difficulty in completing the bowel preparation due to large volume and/or taste, reduced-volume (mixed) bowel preparation of bisacodyl and 2 L of PEG-ELS have been shown to provide adequate colon cleansing and better tolerability.