An observational study with inpatients found that the only dietary modification that improved the quality of preparation was a liquids-only diet[ 63 ]. Its successful implementation depends on many factors, but colon cleansing is a key factor[ 1 ]. However, this has been recognized only recently. A prospective study comparing oral sodium phosphate solution to a bowel cleansing preparation with nutrition food package in children. Pico-salax plus two-day bisacodyl is superior to pico-salax alone or oral sodium phosphate for colon cleansing before colonoscopy. A randomized single-blind trial of standard diet versus fiber-free diet with polyethylene glycol electrolyte solution for colonoscopy preparation. Beyond 14 h after the last dose of the agent, there were no patients with good or excellent cleansing.