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Completed

NCT Number: NCT06916689

Efficacy And Tolerability Of Asymmetric Split Regimen For Bowel Preparation

The investigators aimed to compare the efficacy for bowel cleansing of a split-dose regimen with a low morning dose of PEG solution (Asymmetric; 25% of the dose is given on the day of the procedure and 75% of the dose is given on the day before) with the standard split-dose regimen in patients undergoing screening and surveillance colonoscopy using a very low volume bowel preparation (1L PEG+Ascorbate). Consecutive outpatients undergoing screening and surveillance colonoscopy were enrolled in a randomized, single-blind, non-inferiority clinical trial. Patients were randomly assigned to: group A, asymmetric split dose regimen (0,75 L of PEG + ASC the day before and 0,25 L 2:30 hours before colonoscopy); group B, symmetric split dose regimen (0,5 L of PEG + ASC the day before and 0,5 L 3 hours before colonoscopy). Primary endpoint was the proportion of adequate bowel cleansing. Moreover, all patients filled in a validated, nurse-administered questionnaire assessing compliance, tolerability and safety of bowel preparation.

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Key information

Conditions

Colon Preparation Polyps Colorectal

Age range

50 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

ASST Rhodense

Garbagnate Milanese, Lombardy, 20020, Italy

About this study

Prospective observational, single-blind study conducted in two endoscopy centers belonging to the same Local Health Authority. The two bowel preparation regimens under study (symmetric split and asymmetric split) will be compared in a population of patients undergoing screening for colorectal cancer.

Patient enrollment, product prescription, and the subsequent pre-endoscopic evaluation of safety, tolerability, acceptability, and compliance will be carried out by an assistant who will not be blinded to the type of preparation used.

Endoscopic evaluation, however, will be performed by an experienced endoscopist who will be blinded to the type of bowel preparation administered to the patient.

The bowel preparation product used consists of a very low-volume solution of Macrogol (3350) + Ascorbic Acid (1 liter) (PLENVU®, Norgine).

Bowel cleanliness level assessed using the Boston Bowel Preparation Scale adn overall tolerability of bowel preparation are primary outcomes.

Patient compliance and safety; the number of detected lesions, the percentage of complete colonoscopies, the duration of the colonoscopy, the degree of discomfort/pain perceived by the patient during the examination, and procedure-related complications are secondary outcomes.

Patients will be assigned to the two treatment groups according to a computer-generated sequence.

Data will be expressed as mean and standard deviation for quantitative variables and as frequencies for qualitative variables. The comparison between the two groups will be performed using the t-test for quantitative variables and the chi-square (χ²) test for qualitative variables.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • All patients scheduled as outpatient for screening or surveillance colonoscopy

Exclusion criteria

  • Inpatients
  • refusal of split dose regimen for bowel preparation
  • previous history of colorectal resection
  • severe cardiac disease
  • advanced (stage IV and V) chronic kidney disease
  • pregnancy; ileus
  • suspected bowel obstruction or toxic megacolon
  • known inflammatory bowel disease
  • known or suspected allergy to PEG.

Treatment and study plan

1L PEG-Asc

Drug

PEG 3350 plus sodium sulfate plus sodium chloride plus potassium chloride plus ascorbic acid plus sodium ascorbate

Primary outcomes

  1. Quality of bowel prepreparation

    Time frame: 2 days

    Quality of bowel prepreparation/cleanliness scored using the Boston Bowel Preparation Scale. Each segment of the colon received a score from 0 to 3, and these segment scores were summed for a total BBPS score ranging from 0 to 9. The preparation was considered adequate when BBPS score was ≥ 6 with a score with at least 2 points in any segment

Secondary outcomes

  1. Adenoma detection rate

    Time frame: 2 days

    rate of patients with at least one adenoma

  2. Rate of the occurrence of adverse events

    Time frame: 2 days

    Rate of the occurrence of adverse events (bad taste in mouth, gastric fullness, nausea or vomiting, bloating, abdominal pain, headache)

  3. Compliance

    Time frame: 2 days

    Compliance was assessed by the amount of intake of study agents using a 3-point scale: 1 (100% intake), 2 (≥ 75% intake), and 3 (< 75% intake).

  4. Tolerability of the preparation, as reported by the patient on a Validated Questionnaire

    Time frame: 2 days

    Tolerability was evaluated assessing how patient finds tolerable the bowel preparation by using a 4-point scale: 1 (Easy), 2 (Acceptable), 3 (Somewhat difficult), 4 (Very difficult), plus a Visual Scale with a number from 0 (untolerable) to 100 (very tolerable).

Sponsors and collaborators

Lead sponsor

ASST Rhodense

Other

Registry information

Official study title

Efficacy And Tolerability Of The Asymmetric Split Regimen With A Very Low Volume Bowel Preparation: Split-The-Split Study

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Apr 8, 2025
Registry last updated
Apr 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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