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CompletedNCT05726344Updated Dec 27, 2023

Lactulose vs. Polyethylene Glycol as Bowel Preparation for Colonoscopy in Adults

An interventional study of Lactulose and Polyethylene Glycol 3350 in Lactulose, Polyethylene Glycol and Bowel Preparation, sponsored by Hospital de Clínicas Dr. Manuel Quintela. Completed at 1 site in Uruguay. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-12-27.

Sponsored by Hospital de Clínicas Dr. Manuel Quintela · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
150
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

Colonoscopy is the gold standard in bowel assessment when there is suspicion of colon and rectum pathology. Bowel cleansing is necessary to ensure an optimal visualization of colonic mucosa, allowing this form of detection and removal of polyps. Nowadays international recommendations have multiple bowel preparations. There are differences among them regarding adherence, tolerance and adverse effects. Lactulose (LAC) is widely used in treating constipation. However, there are some randomized clinical assays using LAC as bowel preparation with excellent results according to bowel preparation and tolerance scales. Adherence to bowel preparation significantly affects the result in the endoscopic study.

Safety of polyethylene glycol (PEG) formulations has been validated in several studies, it presents little severe side effects and the advantage of its applicability to patients with several comorbidities (heart, liver and kidney without water deprivation). However, its main disadvantage lies in the need to ingest large amounts of liquid (3-4L), generating intolerance thereto in 15%-45% of patients.

Bowel cleansing preparation with PEG is widely used in clinical practice. Considering that according to international studies reporting better tolerance and adherence with LAC; it is suggested to compare the level of bowel preparation, tolerance and adherence between two groups with LAC and PEG.

02

Conditions studied

  • Lactulose
  • Polyethylene Glycol
  • Bowel Preparation
  • Colonoscopy
  • Bisacodyl
03

In context

Lead sponsor

Hospital de Clínicas Dr. Manuel Quintela is the lead sponsor of 6 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients over 18 years with no bowel surgical procedures

Exclusion criteria

Exclusion Criteria:

  • Patients willingly deciding not to enter into the study
  • Pregnant women
  • Patient with colonic resections and/or ileostomies
  • Inflammatory bowel disease
  • Colonic optimization by prior colonoscopy with poor preparation
  • Suspected intestinal occlusion or perforation, intussusception
  • Patient with melenas
  • Oral iron intake in the past 10 days
  • Emergency colonoscopy
  • to any of the components comprised in preparations.
  • Diabetics
  • Chronic kidney disease in dialysis
  • Uncorrected severe dystonias
  • Severe psychiatric illness (schizophrenia)
  • Low IQ to understand bowel preparation
  • Severe constipation (\< 1 weekly stool)
  • Chronic diarrhea with high rate (≥ 4 daily evenly loose consistency stools for more than 4 weeks)
  • Unbalanced heart diseases (ischemic cardiopathology, congestive heart failure, unstable angina, arrhythmias and untreatable high blood pressure)
  • Ascites
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Care provider, Investigator, Outcomes assessor)
Enrollment
150 participants (actual)

Study arms

  • Experimental
    Lactulose group

    Patients participating in the study shall go on with their usual diet prior to colonoscopy. Three days before avoid consuming fruits, vegetables, seeds and cereals. A low residue soft and liquid diet is allowed. The day before the study, the group receiving lactulose shall take 4 tablets of Bisacodyl (5 mg) the day before the study at 6pm. Then, at 8pm a bottle of 250 mL (162.5g lactulose) of lactulose shall be dissolved in 600 mL of water and all contents (850 mL) shall be taken in 2 hours. At 10pm they have to drink 2 liters still water.

    Drug: Lactulose

  • Experimental
    Polyethylene glycol group

    Patients participating in the study shall go on with their usual diet prior to colonoscopy. Three days before avoid consuming fruits, vegetables, seeds and cereals. A low residue soft and liquid diet is allowed. The day before the study, the group receiving polyethylene glycol (PEG) should take 4 tablets of Bisacodyl (5 mg) at 4pm. Then, at 6pm, 3 bottles of PEG (Polyethylene glycol 3350 60 g; sodium chloride 1.46 g; potassium chloride 745 mg; Sodium bicarbonate 1.68 g; anhydrous sodium sulfate 5.68 g; pineapple flavoring 483 mg) shall be dissolved in 3 liters of water (1 bottle per liter) and they shall take half the preparation, that is 1 liter and a half in 2 hours. At 10pm they shall take the remaining contents in 2 hours.

    Drug: Polyethylene Glycol 3350

Interventions

  • 4 tablets of Bisacodyl (5 mg) + 250 mL (162.5g lactulose) of lactulose + 600 mL of water + 2 L of water

    Also known as: Bisacodyl 20 mg, Water 600 mL

  • 4 tablets of Bisacodyl (5 mg) + 3 bottles Polyethylene Glycol 3350 (Polyethylene glycol 3350 60 g; sodium chloride 1.46 g; potassium chloride 745 mg; Sodium bicarbonate 1.68 g; anhydrous sodium sulfate 5.68 g; pineapple flavoring 483 mg) + 3 L of water

    Also known as: Bisacodyl 20 mg, Water 3 L

06

What researchers measure

Primary outcomes

  1. Compare lactulose vs. Polyethylene Glycol as bowel cleansing preparation for colonoscopy

    Compare the level of bowel preparation (by Boston Bowel Preparation Scale) between two groups with lactulose and Polyethylene Glycol. The minimum and maximum value is 0 and 9, respectively. A proper preparation is consider a Boston Bowel Preparation Scale ≥ 2 scores in each colonic segment. Unsuitable preparation a Boston Bowel Preparation Scale \< 2 scores in any of the segments. Score 0: is considered a segment of unprepared colon with mucosa that cannot be observed given the presence of solid stool which does not disappear after cleansing. Score 1: part of the colonic mucosa is observed; other areas cannot be suitably assessed given the presence of staining, residual matter and/or opaque liquid. Score 2: little remaining residual matter and small matter fragments which do not prevent correct visualization of colonic mucosa in said segment. Score 3: colonic mucosa which can be entirely observed with no residual matter nor small fragments of matter and opaque liquid.

    Time frame: 6 months

  2. Establish Boston Bowel Preparation Scale inter and intra-observer variability

    Two researchers shall review the endoscopic study videos and they shall complete the Boston Bowel Preparation Scale inter-observer questionnaire. Results obtained by the endoscopist in charge of the study and the observers shall be compared so as to establish inter-observer variability. Researchers shall analyze one month later again all colonoscopies recorded thus establishing Boston Bowel Preparation Scale of each endoscopy. Then results previously established shall be compared so as to establish intra-observer variability. The minimum and maximum value is 0 and 9, respectively. A proper preparation is consider a Boston Bowel Preparation Scale ≥ 2 scores in each colonic segment. Unsuitable preparation a Boston Bowel Preparation Scale \< 2 scores in any of the segments.

    Time frame: 7 months

Secondary outcomes

  1. Assess tolerance between lactulose and Polyethylene Glycol.

    To assess tolerance it will be considered: good tolerance those patients with 3 or less symptoms with no major criterion; regular tolerance those patients with 4-5 symptoms, without major criterion and bad tolerance those patients with 6 or more symptoms or 1 or more major criteria.

    Time frame: 6 months

  2. Assess adherence between lactulose and Polyethylene Glycol.

    To assess adherence it shall be assessed if the preparation was completed as well as the will to repeat the same preparation in the future.

    Time frame: 6 months

  3. Assess side effects between lactulose and Polyethylene Glycol.

    To assess side effects of both preparations that will be considered: nausea, vomiting, abdominal pain or bloating, sickness, lipothymia, palpitations, precordial pain, insomnia, anal pain or burning, dry mouth, tinnitus, unpleasant taste.

    Time frame: 6 months

  4. Establish colonoscopy global adenoma detection rate with lactulose and Polyethylene Glycol.

    It correspond to the number of adenomas/adenocarcinomas (histological diagnosis) divided by the total number of colonoscopies performed times 100.

    Time frame: 6 months

  5. Establish colonoscopy cecal intubation rate in with lactulose and Polyethylene Glycol.

    It correspond to the number colonoscopies visualizing ileocecal valve divided by the total number of colonoscopies performed times 100.

    Time frame: 6 months

07

Study locations

1 site
  • Hospital de Clinicas
    Montevideo, Uruguay
08

References and documents

Individual participant data

Plan to share: Yes — Study protocol, Statistical Analysis Plan and Informed Consent Form

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: ENDED THE TRIAL

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Dec 27, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05726344
Lead sponsor
Hospital de Clínicas Dr. Manuel Quintela
Responsible party
Ignacio Moratorio (Principal Investigator, Hospital de Clínicas Dr. Manuel Quintela) — Principal investigator
First posted
Feb 13, 2023
Start date
Feb 10, 2023
Primary completion
Dec 13, 2023
Completion
Dec 13, 2023
Last update
Dec 27, 2023

Study contacts

IGNACIO MORATORIO, MD
principal investigator · HOSPITAL DE CLINICAS
MARIA B RUSSO, MD
principal investigator · HOSPITAL DE CLINICAS
FLORENCIA RODRIGUEZ, MD
principal investigator · HOSPITAL DE CLINICAS

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: Lactulose · Polyethylene glycol 3350

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