Ultra-low Split-dose Oral Lactulose vs High-volume Split-dose Polyethylene Glycol as Bowel Preparation for Outpatient Colonoscopies.

NCT07787897 | Completed

• 2 other identifiers: 09-CEI-011-201606275071
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

This study compared two different ways to clean the bowel before a colonoscopy: lactulose (a sweet syrup mixed with water) versus high-volume polyethylene glycol (PEG, the usual standard treatment). The goal was to find out which one cleans the bowel better, is easier for patients to take, and has fewer side effects. Researchers wanted to answer these main questions: Does lactulose clean the bowel as well as PEG according to the Boston Bowel Preparation Scale? Which preparation do patients find more pleasant and are more willing to repeat in the future? Are there differences in side effects such as nausea, vomiting, bloating, or belly pain? Do the two preparations affect how well doctors can see inside the colon, including the chance of finding polyps? Adults aged 45 to 75 years who were scheduled for a routine outpatient colonoscopy at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City were invited to take part. People with certain serious medical conditions (such as advanced liver disease, kidney failure on dialysis, heart failure, pregnancy, or previous colon surgery) could not join. Participants were randomly assigned to one of two groups: Lactulose group: 125 ml of lactulose mixed in 600 ml of water the evening before, and again early the next morning. PEG group: 2 liters of PEG solution the evening before, and another 2 liters early the next morning. Both preparations were finished by 6:00 a.m. All participants followed a low-fiber diet the day before the procedure. Doctors performing the colonoscopy did not know which preparation each patient had used. The study included 200 people (100 in each group).

Conditions

Colonoscopy

Keywords

colonoscopy; lactulose; low volume bowel preparation

Outcome Measures

Primary Outcomes (3)

• Quality of bowel preparation assessed using the Boston Bowel Preparation Scale (BBPS)

  Total score on the Boston Bowel Preparation Scale (BBPS). The scale evaluates three colon segments (right, transverse, and left), each scored from 0 to 3. The total score ranges from 0 to 9. A higher score indicates better preparation quality. A BBPS score of ≥ 6, with at least 2 points in each segment, is considered adequate preparation.

  During the colonoscopy (day of the procedure)

• Polyp detection rate

  Percentage of colonoscopies in which at least one polyp was detected.

  During the colonoscopy

• Cecal intubation rate

  Percentage of colonoscopies in which the cecum was reached (successful cecal intubation).

  During the colonoscopy

Study Arms (2)

Experimental: Oral lactulose in divided doses

EXPERIMENTAL

Participants receive oral lactulose in divided doses as bowel preparation for outpatient colonoscopy.

Drug: lactulose

Active Comparator: High-volume polyethylene glycol in split doses

ACTIVE COMPARATOR

Participants receive high-volume polyethylene glycol in a split-dose regimen as bowel preparation for outpatient colonoscopy.

Drug: polyethylene glycol (PEG)

Interventions

polyethylene glycol (PEG) DRUG

Polyethylene glycol: 2 sachets of 109.6 grams each, dissolved in 2 liters of water, to be taken between 8:00 PM and 10:00 PM on the night before the study; subsequently, between 4:00 AM and 6:00 AM on the day of the study, another 2 sachets of 109.6 grams each, dissolved in 2 liters of water, are to be administered.

Active Comparator: High-volume polyethylene glycol in split doses

lactulose DRUG

Lactulose: 125 ml of lactulose (10 g/15 ml) in 600 ml of water will be administered between 9:00 PM and 10:00 PM on the night before the study; subsequently, between 5:00 AM and 6:00 AM on the day of the study, another 125 ml of lactulose (10 g/15 ml) in 600 ml of water will be administered.

Experimental: Oral lactulose in divided doses

Eligibility Criteria

• Age: 45 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients scheduled for outpatient colonoscopies for colorectal cancer screening Ages 45 to 75 Informed consent form required

You may not qualify if:

• Pregnancy Patients with colon resections and/or ileostomies Allergy to the medications studied Intolerance to the oral route Hepatic cirrhosis Ascites Chronic kidney disease on peritoneal dialysis or hemodialysis, decompensated heart disease (ischemic heart disease, congestive heart failure, unstable angina) Inflammatory bowel disease Inability to understand the instructions for bowel preparation Suspected intestinal obstruction or perforation Patients with lower gastrointestinal bleeding History of colon cancer History of inadequate bowel preparation History of polyps in previous colonoscopies Bow preparation intake \<50%

Sponsors & Collaborators

• National Institute of Medical Sciences and Nutrition, Salvador Zubiran: lead

Study Sites (1)

National Institute of Medical Sciences and Nutrition Salvador Zubiran

Mexico City, Tlalpan, 14080, Mexico

Location

Related Publications (1)

• https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0045-1805216

  RESULT

MeSH Terms

Interventions

Lactulose; Polyethylene Glycols

Intervention Hierarchy (Ancestors)

Disaccharides; Oligosaccharides; Polysaccharides; Carbohydrates; Sugars; Ethylene Glycols; Glycols; Alcohols; Organic Chemicals; Polymers; Macromolecular Substances; Biomedical and Dental Materials; Manufactured Materials; Technology, Industry, and Agriculture

Study Officials

• Ricardo Macias, Doctor

  National Institute of Medical Sciences and Nutrition, Salvador Zubiran

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: CARE PROVIDER
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Doctor

Study Record Dates

• First Submitted: August 23, 2026
• First Posted: August 26, 2026
• Study Start: July 29, 2024
• Primary Completion: October 30, 2024
• Study Completion: December 31, 2025
• Last Updated: August 26, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

ME (1)