Comparison Between a 1L of Polyethylene Glycol+Ascorbic Acid as a Split Dose Bowel Preparation for Colonoscopy

Inclusion Criteria: * Adult out clinic patients scheduled for colonoscopy for any indication within the normal process of care Exclusion Criteria: * previous history of significant gastrointestinal surgeries (except for appendectomy) * known or clinically suspicious Inflammatory bowel disease patients * known or suspected ileus/ GI obstruction * previous history of major cancer or currently on treating cancer * Major cardiovascular disease, respiratory disease, liver, hematologic diseases with complication * severe cognitive impairment / dementia / confusion state * past history within the last 12 months or current episode of severe constipation severe constipation * Regular use of laxatives or colon motility-altering drugs (i. e. more than 2 - 3 times per week) in the last 28 days prior to screening and/or laxative use within 72 hours prior to administration of the preparation) * women who are pregnant or lactating * known phenylketonuria, glucose-6-phosphate dehydrogenase deficiency * those who were allergic to any preparation components. * those who, in the opinion of the investigator, should not be included in the study for any reason