Impact of a Predictive Score of Bowel Preparation Quality in Clinical Practice

This is a single center randomized controlled trial to compare the colon cleansing quality determined by the Boston Bowel Preparation Scale achieved by two strategies in patients with high risk of poor colon cleansing defined as those patients with a score\> 1.225 following a predictive score previously published: one group will receive an intensified split-dose 4 L polyethylene glycol solution (PEG) plus bisacodyl and 3 days of fiber-free diet and the other group a split-dose 2 L PEG solution with ascorbic plus bisacodyl and 1 day of fiber-free diet. Patients with a score ≤ 1.225 will receive a split-dose 2 L PEG solution with ascorbic plus bisacodyl and 1 day of fiber-free diet.