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Efficacy of Free Versus Low Residue Diet as Preparation for Screening Colonoscopy (CriLi)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT04664543
Recruitment Status : Terminated (Organization and logistic problems due to COVID19 pandemy)
First Posted : December 11, 2020
Last Update Posted : January 26, 2021
Consorci Sanitari de Terrassa
Hospital Mutua de Terrassa
Information provided by (Responsible Party):
Salvador Machlab, Hospital Parc Taulí, Sabadell

Brief Summary:

One tricky aspect of the recommendations for colonoscopy prep is diet. This has a significant impact on the experience of the patient or participant in the screening program and, on the other hand, low adherence has been found in some studies despite a potential Hawthorne effect . It is noteworthy that despite its impact on patient experience, it is an area for which little evidence is available, which is why the guidelines give low-quality recommendations and there is probably considerable variability in clinical practice .

In the early days of colonoscopy, a liquid diet for 48 hours was mainly recommended, although some centers indicated a low-residue diet or even the commercially available NASA astronaut diet. Later, the indication for a liquid diet was consolidated until finally numerous studies were published in favor of a low-residue diet, managing to increase tolerance and the quality of the preparation . A limitation of the preparation studies must be borne in mind that the colon cleansing rating scales were not introduced until 1999 when the Aronchick scale was published.

Although there is solid evidence in favor of a low-residue diet versus a liquid diet, the investigators do not have evidence on how many days of a low-residue diet should be recommended, and this is reflected in the ESGE (European Society of Gastrointestinal Endoscopy) and ASGE (American Society of Gastrointestinal Endoscopy) guidelines . A randomized clinical trial comparing 3 days versus 1 day of a low residue diet has recently been published . There were no statistically significant differences in the rate of adequate preparations (82.7% vs. 85.6% OR 1.2 95% IC 0.72 to 2.15). However, this study has limited statistical power and a design that allows a non-inferiority analysis has not been followed. In relation to this, our research group is finalizing a non-inferiority clinical trial in whose intermediate analysis, with 421 participants, the non-inferiority of 1 day of diet is fulfilled (rate of poor preparation in 1 day 0.95% vs. 4.74% in 3 days; d + 5%, difference -3.78% IC -6.88% to -1.12%) (38).

It is likely, taking into account the available evidence and its evolution, that diet plays a secondary role in preparation. Although no studies designed to directly assess this have been conducted, the research group has indirect data.

Walter et al, under the hypothesis that the impact of the fractional preparation and the new preparations on the preparation diminished the importance of the diet, conducted a non-inferiority clinical trial between 2012 and 2013 in which they randomized the patients to follow a diet liquid versus low residue for one day and fractional preparation with Moviprep (39). They established a non-inferiority margin of -13.5%. Their results show a rate of good preparation (Boston> 5) in 68/72 (94.4%) in a liquid diet compared to 60/68 (88.2%) in a low-residue diet (p = 0.04) with a difference of -5.08% demonstrating non-inferiority of the low residue diet.

Condition or disease Intervention/treatment Phase
Colorectal Cancer Colon Polyp Colon Adenoma Other: Free diet Other: Three days low residue diet Not Applicable

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: Efficacy of Free Versus Low Residue Diet as Preparation for Screening Colonoscopy: CriLi Study, a Pilot Trial
Actual Study Start Date : December 1, 2019
Actual Primary Completion Date : December 30, 2020
Actual Study Completion Date : December 30, 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Colonoscopy

Arm Intervention/treatment
Active Comparator: 3 days of low residue diet
Currently participants in the colorectal cancer screening program follow a 3 days low residue diet before colonoscopy. This is the active comparator arm of this study.
Other: Three days low residue diet
To follow the three days before colonoscopy a diet with low content in fiber or residues.
Other Name: low fiber diet

Experimental: Free diet
Participants assigned to this arm are NOT instructed to follow any kind of restriction in the diet before colonoscopy.
Other: Free diet
To follow the regular dietary habits with no restriction nor modification.
Other Name: Liberal diet, habitual diet

Primary Outcome Measures :
  1. Adequate bowel cleansing [ Time Frame: During colonoscopy (At the withdrawal phase) ]
    Bowel cleansing has a rating using the Boston Bowel Preparation Scale above 1 in each segment . This score ranges fron 0 to 3 in each one of the three segments. Zero is the worst outcome and 3 is the best cleansing

Secondary Outcome Measures :
  1. Diet tolerability [ Time Frame: The day of the colonoscopy just before beginning ]
    Tolerance to the diet assigned to the participant measured with a likert scale from 0 to 5, 0 the worst ad 5 the best.

  2. Preparation tolerability [ Time Frame: The day of the colonoscopy just before beginning ]
    Tolerance to the cleansing solution used for bowel cleansing measured with a likert scale from 0 to 5, 0 the worst ad 5 the best.

  3. Adenoma detection [ Time Frame: adenoma detection is done during the colonoscopy but assesment will be done at the end of the study with the histology reports ]
    An adenoma was detected, resected and confirmed by the histology report in the colonoscopy.

  4. Polyp detection [ Time Frame: During colonoscopy ]
    Polyp detection in the colonoscopy as reported by the endoscopist.

  5. Ceacal intubation time [ Time Frame: During colonoscopy ]
    Time expended in reaching the cecum

  6. Withdrawal time [ Time Frame: During colonoscopy ]
    Time expended in the withdrawal from cecum till the anus.

  7. Excellent cleansing [ Time Frame: During colonoscopy ]
    Colonoscopy achieving a Boston Bowel Preparation Scale (BBPS) of at least 8 points or above. BBPS global score ranges from 0 to 9, being 9 the best cleansing outcome.

  8. Information perceived quality [ Time Frame: The day of the colonoscopy just before beginning ]
    Perceived quality of the instructions and education received for the colonoscopy. preparation by the participant. Assessed using a likert scale from 0 to 5. Five is the best outcome and 0 the worst.

  9. Preparation quality in each segment [ Time Frame: During colonoopy ]
    Boston Bowel Preparation Score in each segment, it ranges from 0 to 3 being 3 the best cleansing outcome and 0 the worst.

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years to 69 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Men and women between 50 and 69 years old.
  • Participants in the Program for the Early Detection of Colorectal Cancer with a positive result in the test for detecting occult blood in feces
  • That they accept a colonoscopy and that they agree to participate in the study.

Exclusion Criteria:

  • Contraindication to performing a colonoscopy.
  • Severe renal insufficiency (<30 ml / min).
  • Known hypersensitivity or allergy to polyethylene glycol, ascorbic acid or sulfate.
  • Known glucose-6-phosphate dehydrogenase deficiency.
  • Known phenylketonuria.
  • Known dyselectrolytemia: hyper / hyponatremia, hyperphosphatemia, hypermagnesemia, hyper / hypokalemia, hypocalcemia.
  • Gastric emptying disorders: Known gastroparesis.
  • Known hypoalbuminemia less than 3.4 g / dl.
  • Crohn's disease or known ulcerative colitis.
  • Participants with difficult-to-control hypertension (SBP> 170mmHg or TAD> 100mmHg) or NYHA grade III or IV heart failure.
  • Ascites of any etiology
  • People with cognitive impairment or mental illness that makes it difficult to adhere to instructions.
  • People who do not understand Catalan or Spanish.
  • Factors of poor preparation: liver cirrhosis, diabetes mellitus, treatment with tricyclic antidepressants, opioids or neuroleptics, limited mobility, chronic constipation, history of colon or intestinal resection (appendectomy is not an exclusion criterion), poor preparation in previous colonoscopy Parkinson's disease, multiple sclerosis.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04664543

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Hospital Universitari Parc Taulí
Sabadell, Barcelona, Spain, 08208
Sponsors and Collaborators
Hospital Parc Taulí, Sabadell
Consorci Sanitari de Terrassa
Hospital Mutua de Terrassa
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Study Director: Eva Martínez, PhD Hospital Universitari Parc Taulí
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Responsible Party: Salvador Machlab, Principal Investigator, Hospital Parc Taulí, Sabadell
ClinicalTrials.gov Identifier: NCT04664543    
Other Study ID Numbers: 2019307
First Posted: December 11, 2020    Key Record Dates
Last Update Posted: January 26, 2021
Last Verified: January 2021

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Salvador Machlab, Hospital Parc Taulí, Sabadell:
bowel cleansing
low fiber diet
colonoscopy preparation
Additional relevant MeSH terms:
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Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type