Bowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study.

Recruitment Status
COMPLETED - HAS RESULTS
(See Contacts and Locations)Verified May 2026 by Hospital Civil de Guadalajara
Sponsor
Hospital Civil de Guadalajara
Information Provided by (Responsible Party)
Roberto Ulises Cruz Neri
Clinicaltrials.gov Identifier
NCT06666556
Other Study ID Numbers:
151/24
First Submitted
October 27, 2024
First Posted
October 29, 2024
Results First Posted
February 18, 2026
Last Update Posted
July 27, 2026
Last Verified
May 2026

ClinicalTrials.gov processed this data on June 2026Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

A bowel preparation is fundamental before making a colonoscopy, letting us realize a correct exploration in all the bowel. The main method of cleaning would be fast, safe and getting a high grade of visualizing to do a quality colonoscopy.

Actually there are a lot of methods or products of cleaning the bowel. A good cleaning have a lot of successful choosing a good product to do it and having a good diet before the colonoscopy.

There are a lot of scales about the cleaning in the colonoscopy, having a good bowel preparation increase the capacity of the detection of polyps, decrease the time of the colonoscopy and getting better the cost and efficiency.

The colonoscopy plays a crucial role in the screening and treatment of colorectal cancer. It is an optimal procedure to identify precancerous lesions. polyps and recommended for screening people with risk factors, such as a family history of polyps or cancer.

Bowel preparation is a crucial aspect in colonoscopy due to its direct relationship with the quality of the procedure. Many patients find bowel preparation to be the most uncomfortable part of the examination, so ensuring that it is safe, extremely efficient, reliable, convenient and tolerable enough to ensure that patients will not be able to complete it or wish to undergo future procedures, associating this with the bad taste of the agents used and the adverse events produced.

Ignorance of the importance of adequate bowel preparation and cleansing explains poor adherence to instructions, and increases the rate of inadequate bowel preparation.

The health team must provide correct and clear information that improves patient adherence. The importance of compliance with the indications and the impact of adequate intestinal cleansing on the findings and results of colonoscopy should be emphasized.

The cleaning systems used in colonoscopy must allow more than 90% of the mucosal surface to be explored. Furthermore, the drugs used must be well tolerated by the patient and not cause side effects. Therefore, the ideal colonoscopy preparation should combine efficacy, excellent tolerance, and minimal adverse effects.

The use of oral bowel preparations may induce strong peristalsis, cramps, bloating, diarrhea and other symptoms. Intolerance to the preparation is common and is usually associated with the volume of liquid consumed and the taste of the solution.

Polyethyleneglycol (Muvinlax(r) or Nulytely is a non-absorbable electrolyte solution and does not induce electrolyte mucus secretion or significantly reduce fluid exchange in the colonic lumen. It has been shown to be non-toxic and can be ingested in large quantities without dangerous effects. Its use is relatively safe in patients with kidney failure, cirrhosis or congestive heart failure.

Bowel preparation with polyethyleneglycol represents the most used formula in our environment. Among the recognized limitations associated with its application are: the large amount of volume to be ingested (4 L), which makes it impossible to administer it to elderly people with swallowing difficulties, it is also poorly tolerated by patients and has been associated with medical complications, among which can be mentioned: vomiting, abdominal distension, abdominal pain, nausea, Mallory Weiss syndrome, esophageal perforation, bronchoaspiration, toxic colitis, pancreatitis induced by polyethyleneglycol.

Lactulose (Duphalac (r)) is a disaccharide, semi-synthetic derivative of lactulose. It is absorbed and undergoes bacterial action, which causes fermentation, acidifying the environment and causing acceleration of intestinal transit, stimulating motility. Another consequence of acidification is the increase in osmotic pressure within the lumen of the colon, proportional to the dose. Regarding the dose, 120 ml are diluted with juice or clear water until completing 1000 ml, swallowing the entire volume in 1 hour The preparation regimen has a significant impact on the quality of intestinal cleansing. Traditionally, preparation is done one day before a colonoscopy.

Condition or DiseaseIntervention/Treatment
Colorectal Cancer Screening
Combination Product: Bowel preparation before colonoscopyCombination Product: Bowel preparation before colonoscopy

Study Design

Study TypeInterventional
Actual Enrollment449 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingSingle
Primary PurposeScreening
Official TitleBowel Preparation in Colonoscopy: Lactulose vs Polyethyleneglycol, Randomized Double-blind Comparative Clinical Trial, Multicenter Study.
Study Start DateJuly 19, 2024
Actual Primary Completion DateJuly 30, 2025
Actual Study Completion DateAugust 13, 2025

Groups and Cohorts

Group/CohortIntervention/Treatment
Bowel preparation with lactulose before de colonoscopy
Patients will be randomized and assigned the bowel preparation the day that provide them the day of the colonoscopy
Combination Product: Bowel preparation before colonoscopy
In this multicenter single-blind randomized clinical trial study we will provide each patient that meets our inclusion criteria a randomized folio to include them in one of both arms in our protocol, meaning one of the groups and the bowel preparation assigned to perform the colonoscopy, they will be explained the benefits and minimum risks of participating and they will also be asked to sign an informed consent form so we can continue with the colonoscopy and collect all the data we need for our protocol and the analysis of the variables.
Bowel preparation with plyethylenglycol before the colonoscopy
Patients will be randomized and assigned the bowel preparation the day that provide them the day of the colonoscopy
Combination Product: Bowel preparation before colonoscopy
In this multicenter single-blind randomized clinical trial study we will provide each patient that meets our inclusion criteria a randomized folio to include them in one of both arms in our protocol, meaning one of the groups and the bowel preparation assigned to perform the colonoscopy, they will be explained the benefits and minimum risks of participating and they will also be asked to sign an informed consent form so we can continue with the colonoscopy and collect all the data we need for our protocol and the analysis of the variables.

Outcome Measures

Primary Outcome Measures
  1. Bowel Cleansing Was Assessed Using the Boston Bowel Preparation Scale (BBPS).
    Bowel cleansing quality was assessed using the Boston Bowel Preparation Scale (BBPS), which evaluates three segments of the colon (right, transverse, and left), each scored from 0 to 3, with a total score ranging from 0 to 9. Higher scores indicate better bowel preparation.
Secondary Outcome Measures
  1. Number of Participants With Gastrointestinal Side Effects
    Number of participants presenting gastrointestinal symptoms related to bowel preparation, including nausea, vomiting, abdominal pain, or abdominal distension.
  2. Number of Participants Who Tolerated the Assigned Bowel Preparation
    Tolerability was assessed through direct patient questioning after completion of bowel preparation. Participants were classified as having tolerated or not tolerated the assigned bowel preparation according to their overall subjective experience. The analysis population consisted only of participants who completed the assigned bowel preparation and underwent colonoscopy. Participants excluded because of intolerance to the preparation were not included in this outcome analysis.
  3. Number of Participants Who Found the Bowel Preparation Palatable
    Palatability was assessed by asking participants whether the taste of the assigned bowel preparation was acceptable. Participants were classified as having found the preparation palatable or not palatable based on their subjective response.

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersYes
Inclusion Criteria
Patients with indication for colonoscopy in our coloproctology service
Both women and men
Patients within an age range of 18-79 years
Patients who agree having a colonoscopy and who sign the informed consent to participate in the protocol
Exclusion Criteria
Patients under 18 or over 80 years old
All patients that won´t like to participate in the protocol or won´t sign the informed consent
Pregnant women
Patients with a medical record of colonic resection, ostomy status, severe cardiopulmonary and renal diseases, major psychiatric disorders, therapeutic colonoscopy or any contraindications for colonoscopy
Non compliance with the colonic preparation regimen
Active bleeding during the procedure
Patients with a known diagnosis of colorectal cancer

Contacts and Locations

Sponsors and CollaboratorsHospital Civil de Guadalajara
Locations
Antigüo Hospital Civil de Guadalajara "Fray Antonio Alcalde" | Guadalajara Jalisco, Mexico, 44200Nuevo Hospital Civil de Guadalajara "Juan I. Menchaca" | Guadalajara Jalisco, Mexico, 44340IMSS Hospital General Regional 220 "José Vicente Villada" | México Toluca de Lerdo, Mexico, 50150
Study Documents (Full Text)
Documents provided by Hospital Civil de GuadalajaraStudy Protocol and Statistical Analysis Plan  June 29, 2026