This study aims at developing a new objective method of assessing the quality of bowel preparation during colonoscopy.

1. Finding an association between the "Fecacrit" (measured solid residue from bowel preparation solutions) and the quality of bowel preparation (excellent, good, fair) as measured by the Aronchik, Ottawa and Boston bowel preparation scales. (primary objective)

200 Consecutive patients undergoing screening colonoscopy will be prospectively enrolled in this study. Stool remnants will be collected from colonoscopies that are deemed adequate (prior to washing) and will undergo centrifugation in order to measure proportion of solid residues and associate the measured residue with the different scales used to score the bowel preparation quality by the endoscopist.

200 stool samples from successful colonoscopies that are deemed adequate in quality will be consecutively collected in sample cups prior to washing. These samples will then be transferred to tubes and will undergo centrifugation for 15 minutes before discarding the supernatant and weighing the residue. 80 samples will make up the derivation cohort while the following 120 samples will serve as validation samples.