123 Single Day Low Residue Diet Prior to Colonoscopy Shows Improved Bowel Preparation Quality and Patient Tolerance Over Clear Liquid Diet: Final Results From a Randomized, Single-Blinded, Dual Center Study

Abstract

INTRODUCTION: Patients often cite bowel preparation and associated dietary restrictions as the greatest deterrents to having a colonoscopy completed or performed. Large studies comparing low residue diet (LRD) and clear liquid diet (CLD) are still limited. The aim of this study was to compare LRD and CLD with regards to bowel preparation quality, tolerance, and satisfaction among a diverse patient population. METHODS: This study is a dual center, randomized, single blinded, prospective trial involving adult patients undergoing outpatient colonoscopy at the University of California Irvine Medical Center and a Veterans Administration hospital. Patients were randomized to consume either a CLD or a planned LRD for the full day prior to colonoscopy. Both groups consumed 4L split-dosed PEG-ELS. The adequacy of bowel preparation was evaluated using the Boston Bowel Preparation Score (BBPS). Adequate preparation was defined as a BBPS ≥7. Hunger and fatigue pre and post procedure were graded on a 10-point scale. Nausea, vomiting, bloating, abdominal cramping, overall discomfort, satisfaction with the diet, willingness to repeat the same preparation and overall experience were assessed. RESULTS: A total of 170 subjects who underwent colonoscopy from October 2014 to October 2017 were included. The mean BPPS for the LRD and CLD groups was 7.98 and 7.54, respectively. There was a significantly higher number of adequate preparations in the LRD group compared to CLD (P = 0.05). Evening hunger scores just before starting the bowel preparation were significantly lower in the LRD than CLD group, 5.5 vs 7.03, respectively (P = 0.006). Subjects in the LRD group showed significantly less nausea (P = 0.047) and bloating (P = 0.04). Symptom scores for vomiting, abdominal cramping, and overall discomfort were similar between the groups. Satisfaction with diet was significantly higher in the LRD group than CLD, 100% vs 33% respectively (P < 0.001). The overall colonoscopy experience and the satisfaction with the preparation itself were also better reported in the LRD group (P = 0.002). CONCLUSION: This study demonstrated that the use of a LRD before colonoscopy achieves a superior bowel preparation quality compared to CLD. Low-residue diet also improves patient satisfaction and results in significantly better tolerability of bowel preparation. As a less restrictive dietary regimen, low-residue diet may help improve patient participation in colorectal cancer screening programs.