Optimizing colonoscopy preparation: the role of dosage, timing and diet

The focus of this review is to review recent literature on colonoscopy preparation, in order to determine what regime currently results in the highest rates of adequate bowel cleansing, in terms of the substance used, its dosing, timing and the role of dietary restrictions during preparation.

Recent data have emphasized that poor bowel preparation is frequent and results in significant healthcare costs and risks to patients in terms of missed neoplasia, which may be particularly important in the proximal colon. Polyethylene glycol (PEG) preparation is superior to, and safer, than sodium phosphate preparation, and results are further improved by split-dose regimes. Regular diet until dinner, the day before colonoscopy does not impair preparation in the context of split-dose PEG regimes.

Available data indicate that the optimal colonoscopy preparation regime is the split-dose PEG regime with regular diet until dinner. Strategies for patients with difficulties in achieving adequate bowel cleansing with standard regimes remains a difficulty. The role of adjuncts, such as bisacodyl, is also less defined.