Optimal and safe bowel preparation for colonoscopy.

Effective colonoscopy requires an adequate level of cleansing as a basic component. This review will describe a compact review about general considerations in bowel preparation for colonoscopy and specific considerations for various patients. A low-fiber diet instead of a regular diet on the day before colonoscopy is an independent predictor of adequate bowel preparation. Improved bowel cleansing does not result from the routine use of enemas or prokinetics in addition to oral bowel preparation. For morning colonoscopy, a split method of 4 L polyethylene glycol on the day before and the day of colonoscopy is recommended, while patients scheduled for afternoon colonoscopy typically receive a full method of 4 L polyethylene glycol on the day of the procedure. Valid alternatives are 2 L polyethylene glycol plus ascorbic acid or 2 L sodium picosulphate plus magnesium citrate. Although there are no statistically significant differences between polyethylene glycol and oral sodium phosphate for colon cleansing, polyethylene glycol-based bowel preparation is advisable in most situations because of safety concerns.