Impact of a 1-day versus 3-day low-residue diet on bowel cleansing quality before colonoscopy: a randomized controlled trial

Abstract

Background The aim of this study was to assess whether a 3-day low-residue diet (LRD) improved bowel cleansing quality compared with a 1-day LRD regimen. Methods Consecutive patients scheduled for outpatient colonoscopy were randomized to the 1-day LRD or 3-day LRD groups. All patients received a 2-L split-dose of polyethylene glycol plus ascorbic acid. The primary outcome was bowel cleansing quality as evaluated using the Boston Bowel Preparation Scale (BBPS) (adequate cleansing ≥ 2 points per segment). Secondary outcomes were adherence to and level of satisfaction with the LRD, difficulty following the dietary recommendations, and willingness to repeat the same LRD in the future. Intention-to-treat (ITT) and per-protocol (PP) analyses were conducted for the primary outcome. A superiority analysis was performed to demonstrate that a 3-day LRD regimen was superior to a 1-day LRD regimen with a margin of 10 %. Results 390 patients (1-day LRD group = 196, 3-day LRD = 194) were included. The cleansing quality was not significantly different between the groups: ITT analysis 82.7 % (95 % confidence interval [CI] 77.4 to 88.0) vs. 85.6 % (95 %CI 80.7 to 90.5), with odds ratio (OR) 1.2 (95 %CI 0.72 to 2.15); PP analysis 85.0 % (95 %CI 79.9 to 90.1) vs. 88.6 % (95 %CI 84.0 to 93.2), with OR 1.4 (95 %CI 0.88 to 2.52). No differences were found regarding adherence to the diet or cleansing solution, satisfaction or difficulty with the LRD, and the polyp/adenoma detection rates. Conclusion 3-day LRD did not offer advantages over 1-day LRD in preparation for colonoscopy.

A 3‐day low‐fibre diet does not improve colonoscopy preparation results compared to a 1‐day diet: A randomized, single‐blind, controlled trial

“…Finally, our results are based in a standard 4L PEG solution and we cannot generalize our conclusion to other laxatives, although the similar protocol was recently published where a low-volume 2L PEG plus ascorbic acid was used with similar results. 13 Concluding, the recommendation of a 3-day LFD does not bring added value to the bowel preparation quality especially if performing split-dose. Increasing the time of diet can also increase the difficulty of the overall preparation, possibly undermining the result.…”

“…In addition, no recommendations are made regarding the use of an LFD for more than 24 hours before the procedure, although the experts recognize a group of endoscopists routinely prescribing the recommended diet for a 3-day period prior to the colonoscopy; however, at the time only one study is published comparing both dietary prescriptions. 3,13 Therefore, the purpose of this study was to test the influence of a 3-day versus 1-day LFD in bowel preparation results and the effect on patient tolerability and adherence, in a general population of outpatients undergoing colonoscopy.…”

Comparison of the effect of 1-day and 2-day low residue diets on the quality of bowel preparation before colonoscopy

“…Antonio et al . [ 14 ] compared the quality of bowel preparations of outpatients using 1-day and 3-day LRDs and found that the 3-day LRD had a bowel preparation quality similar to that of the 1-day LRD.…”

Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline – Update 2019

“…A further four recent RCTs have also shown that patient satisfaction, ease of preparation, and willingness to repeat an identical preparation were higher with a low residue diet vs. a clear liquid diet in all trials that analyzed those outcomes (3, 2, and 1 RCTs, respectively); and the proportions of patients with adequate bowel preparation (3 RCTs) were similar or higher with a low residue diet vs. a clear liquid diet (Table 1s, Appendix 3s, online-only Supplementary Material) [18,19,27,28]. Recently, a possible additional effect of multiple-day vs. singleday low residue diet among participants receiving a split-dose bowel preparation has been excluded in a randomized trial [29].…”