Randomized Clinical Trial : A Normocaloric Low-Fiber Diet the Day Before Colonoscopy Is the Most Effective Approach to Bowel Preparation in Colorectal Cancer Screening Colonoscopy

Clinical guidelines recommend either a clear-liquid diet or a low-fiber diet for colonoscopy preparation. Participants in a screening program are usually motivated healthy individuals in which a good tolerability is important to improve adherence to potential surveillance colonoscopies. Our aim was to assess whether or not a normocaloric low-fiber diet followed the day before a screening colonoscopy compromises the efficacy of bowel cleansing and may improve the tolerability of bowel preparation. This is a randomized, endoscopist-blinded, noninferiority clinical trial. The study was conducted at a tertiary care center. A total of 276 consecutive participants of the Barcelona colorectal cancer screening program were included. Participants were randomly assigned to a clear-liquid diet or a normocaloric low-fiber diet the day before the colonoscopy. Both groups received 4 L of polyethylene glycol in a split-dose regimen. Primary outcome was the adequate bowel preparation rate measured with the Boston bowel preparation scale. Secondary outcomes included tolerability, fluid-intake perception, hunger, side effects, and acceptability. Participants in both groups were similar in baseline characteristics. Adequate bowel preparation was achieved in 89.1% vs 95.7% in clear-liquid diet and low-fiber diet groups, showing not only noninferiority, but also superiority (p = 0.04). Low-fiber diet participants reported less fluid-intake perception (p = 0.04) and less hunger (p = 0.006), with no differences in bloating or nausea. The single-center design of the study could limit the external validity of the results. The present findings may not be comparable to other clinical settings. A normocaloric low-fiber diet the day before a screening colonoscopy achieved better results than a clear-liquid diet in terms of adequate colon preparation. Moreover, it also improved the perception of hunger and excessive fluid intake

Efficacy of a multifactorial strategy for bowel preparation in diabetic patients undergoing colonoscopy: a randomized trial.

Background and study aims: Previous studies have reported that diabetes mellitus is an independent risk factor for inadequate bowel preparation. Current guidelines do not recommend a specific preparation for this patient population. The aims of this study were to assess the efficacy, safety, and tolerability of an adapted preparation protocol for colon cleansing in patients with type 2 diabetes mellitus. Patients and methods: This randomized, single-blind, parallel group, superiority trial compared a conventional bowel preparation protocol (CBP) with a diabetes-specific preparation protocol (DSP). The CBP included a low-fiber diet for 3 days followed by a clear liquid diet for 24 hours before colonoscopy. The DSP included a multifactorial strategy combining an educational intervention, a low-fiber diet, and adjustment of blood glucose-lowering agents. All patients received 4 L of a polyethylene glycol solution in a split-dose regimen. The endoscopists were blinded to the preparation protocol. The primary outcome measure was inadequate bowel preparation according to the Boston Bowel Preparation Scale. Secondary outcome measures included hypoglycemic events, tolerability, and acceptability. Results: A total of 150 patients were included in the study (74 CBP and 76 DSP). Both groups were comparable in terms of baseline characteristics. Inadequate bowel cleansing was more frequent following CBP than DSP (20 % vs. 7 %, P = 0.014; risk ratio 3.1, 95 % confidence interval 1.2 - 8). Only CBP and performance status were independently associated with inadequate bowel preparation. Both preparations were equally tolerated and accepted by patients, and side-effects were similar between the groups. Conclusions: A multifactorial strategy for bowel preparation in patients with diabetes undergoing colonoscopy showed a threefold reduction in the rate of inadequate bowel preparation, with no differences in safety and tolerability compared with conventional preparation