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

NCT ID: NCT04664543

Last Updated: 2021-01-26

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: NA
• Total Enrollment: 100 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-12-01
• Study Completion Date: 2020-12-30

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.

Conditions

Colorectal Cancer; Colon Polyp; Colon Adenoma

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: TRIPLE

Study Groups

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.

Group Type: ACTIVE_COMPARATOR

Three days low residue diet

Intervention Type: OTHER

To follow the three days before colonoscopy a diet with low content in fiber or residues.

Free diet

Participants assigned to this arm are NOT instructed to follow any kind of restriction in the diet before colonoscopy.

Group Type: EXPERIMENTAL

Free diet

Intervention Type: OTHER

To follow the regular dietary habits with no restriction nor modification.

Interventions

Free diet

To follow the regular dietary habits with no restriction nor modification.

Intervention Type: OTHER

Three days low residue diet

To follow the three days before colonoscopy a diet with low content in fiber or residues.

Intervention Type: OTHER

Other Intervention Names

Liberal diet, habitual diet; low fiber diet

Eligibility Criteria

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.

• Minimum Eligible Age: 50 Years
• Maximum Eligible Age: 69 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Consorci Sanitari de Terrassa

OTHER

Sponsor Role: collaborator

Hospital Mutua de Terrassa

OTHER

Sponsor Role: collaborator

Parc Taulí Hospital Universitari

OTHER

Sponsor Role: lead

Responsible Party

Salvador Machlab

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Eva Martínez, PhD

Role: STUDY_DIRECTOR

Hospital Universitari Parc Taulí

Locations

Hospital Universitari Parc Taulí

Sabadell, Barcelona, Spain

Countries

Spain

References

Machlab Mashlab S, Martinez-Bauer E, Lopez P, Pujals MDM, Fernandez-Banares F, Selva A, Calvet X, Campo R. Unrestricted vs three-day low-residue diet for colonoscopy preparation. Results of a feasibility randomized trial. Rev Esp Enferm Dig. 2025 Jun;117(6):349-350. doi: 10.17235/reed.2024.10417/2024.

Reference Type: DERIVED

PMID: 38591600 (View on PubMed)

Other Identifiers

2019307

Identifier Type: -

Identifier Source: org_study_id