Mo1122 Effects of Low-Residue Diet Prior to Day of Screening Colonoscopy on Bowel Preparation Quality

Background: Poor colonoscopy preparation alters the ability to detect pre-cancerous colon adenomas in patients undergoing screening colonoscopy.One of the limitations to colon cleanliness is patient non-compliance and dissatisfaction with prescribed bowel prep and clear liquid diet prior to colonoscopy.This may result in missed pre-cancerous lesions and the need for more frequent follow-up or repeat colonoscopy resulting in increased healthcare spending.Methods: This was a prospective, randomized, single-blinded (endoscopist) study performed at a single institution.Patients undergoing screening colonoscopy were randomly assigned to low-residue diet (LRD) or clear-liquid diet (CLD) the day prior to colonoscopy in addition to standard GoLytely split bowel prep.Patients 45-70 years of age undergoing outpatient screening colonoscopy were included in the study.Exclusion criteria were: history of colorectal surgery, colonoscopy indication other than screening/surveillance, or multiple, significant co-morbidities.Patients were provided sample diet menus, and a bowel prep satisfaction questionnaire prior to colonoscopy.Blinded endoscopists rated colon cleanliness based on the Boston Bowel Prep score (BBP) with a max score of 9 (max of 3 per bowel region) indicating a perfectly clean colon.The primary outcome was similar efficacy of LRD compared to CLD in bowel cleanliness.Secondary outcomes included: adenoma detection rate and patient satisfaction of the bowel prep compared amongst the two diets.Results: A total of 139 patients participated, 70 patients were assigned to CLD and 69 to LRD groups.There was no statistical difference in patient characteristics including age, sex, history of diabetes, hypertension, and narcotic or tobacco use.Average BBP score was 7.06 for CLD and 7.46 for LRD (p= 0.26).Average BBP score by colon region (right, transverse, or left colon) was 2.23, 2.41, and 2.42 respectively for CLD and 2.45, 2.51, and 2.49 respectively for LRD (p = 0.16, 0.37, 0.60).Statistically, there was no difference between CLD and LRD in total or regional BBP score.Overall, adenoma detection rates were similar at 52% in CLD group and 55% in LRD group with little difference between adenoma detection rate for screening versus surveillance colonoscopy amongst the groups (p= 0.63).Additionally, there was no statistical difference in side effect profile or patient satisfaction amongst CLD and LRD groups.Conclusion: Based on our preliminary results, LRD prior to screening colonoscopy was no less effective than CLD in bowel cleanliness based on BBP scores.There was no statistical difference in adenoma detection rate between the two diets and there was no difference in patient side-effect profile or overall satisfaction of the bowel prep.