Low-fiber Diet for Colorectal Cancer Screening Colonoscopy (DIETCOL)

This trial will compare the efficacy of 2 different sets of dietary recommendations to be followed before colon cleansing for colorectal cancer screening colonoscopy.

There is no enough evidence in the literature to recommend a low-fiber diet for screening colonoscopy. Although evidence of benefit of a liquid diet is minimal and there is a growing body of evidence about the benefits of a liberalized diet, a high degree of heterogeneity in the clinical trials comparing the diet modifications before colonoscopy prevents a formal recommendation in current guidelines. A low-fiber diet the day before colonoscopy may result in same efficacy of bowel cleanliness, with an improved tolerability and acceptability. All consecutive patients of a population-based colorectal screening cancer program referred for a colonoscopy will be invited to participate in the study. After obtaining informed consent, they will be randomized to one of the groups: liquid diet or low-fiber diet. The will be interviewed by a registered research nurse, and they will be provided with written instructions for bowel preparation and questionnaires for registering the data of the study. The day of the colonoscopy, questionnaires will be collected and endoscopists blinded for the study bowel preparation will perform the colonoscopy. Patients will be contacted for adverse events and a general satisfaction questionnaire, 3 days after colonoscopy.

Colonoscopy, Diet, Polyethylene glycols, Efficacy, Personal satisfaction, Colorectal cancer screening

The experimental group will receive 4 days of low-residue diet Laxative 4 liters polyethylene glycol 4000 in split fashion.

The control group will receive 3 days of low-residue diet followed by 24 hours of liquid diet. Laxative 4 liters polyethylene glycol 4000 in split fashion.

Subjects will be instructed by members of the research team to follow a standardized low residue diet for 4 days

Subjects will be instructed by members of the research team to follow a low-residue diet for 3 days followed by 24 hours of liquid diet

The efficacy of bowel preparation will be rated by blinded endoscopists using the Boston Bowel Preparation Scale (BBPS). Colonoscopies with a BBPS score of less than 5 points, or any segment rated less than 2 points will be considered with an inadequate bowel preparation

Inclusion criteria: Consecutive patients referred for a colonoscopy in a population-based colorectal screening program. Exclusion criteria: Unwillingness to participate. Inability to follow instructions Active inflammatory bowel disease Incomplete colonoscopies for technical reasons or contraindication as evaluated by the endoscopist

Soweid AM, Kobeissy AA, Jamali FR, El-Tarchichi M, Skoury A, Abdul-Baki H, El-Zahabi L, El-Sayyed A, Barada KA, Sharara AI, Mourad F, Arabi A. A randomized single-blind trial of standard diet versus fiber-free diet with polyethylene glycol electrolyte solution for colonoscopy preparation. Endoscopy. 2010 Aug;42(8):633-8. doi: 10.1055/s-0029-1244236. Epub 2010 Jul 9.

Alvarez-Gonzalez MA, Pantaleon MA, Flores-Le Roux JA, Zaffalon D, Amoros J, Bessa X, Seoane A, Pedro-Botet J; PROCOLON group. 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. Dis Colon Rectum. 2019 Apr;62(4):491-497. doi: 10.1097/DCR.0000000000001305.