Bowel Preparation SolutionsPhase 4NCT04474002
Efficacy, Tolerance and Safety of Split Dose Bowel Preparation for Colonoscopy: 4L Polyethylene Glycol (PEG) Versus 1L Polyethylene Glycol Plus Sodium Picosulfate-magnesium Citrate (SPMC)
A Phase 4 study testing 4L Klean Prep® and 1L Klean prep® and 2 sachets Picoprep® in people with Bowel Preparation Solutions and Colonoscopy, run by Queen Elizabeth Hospital, Hong Kong at 1 site in Hong Kong.
Trial summary
4L split dose PEG is the gold standard for bowel preparation, however it comes with poor tolerability and poor compliance. Combination of PEG with different agent is useful in reducing total volume, improving compliance and tolerance of patient. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Bowel Preparation Solutions, Colonoscopy
- What is being tested?
- 4L Klean Prep® and 1L Klean prep® and 2 sachets Picoprep®
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 158 participants
- Where
- 1 siteHong Kong
- Study dates
- 7 Dec 2020to 31 Dec 2022
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Patient who mentally capable to consent for participating the trial
- 18 - 65 years old
- Scheduled for 1st colonoscopy
- Elective outpatient colonoscopy
Who cannot join
- Prior colorectal or abdominal-pelvic surgery
- Inflammatory bowel disease
- Active bowel condition eg intestinal obstruction
- Gastrointestinal disorders eg active ulcer, gastric outlet obstruction, gastroparesis and hypomotility syndrome
- Recent myocardial infarction, congestive heart failure, uncontrolled hypertension
- Renal dysfunction, hepatic disease
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- Patient on long term tranquilizer, anti-spasmodic, prokinetic, laxative or antidiarrhoeal agents
- Hypersensitivity to PEG or SPMC solution
- Pregnant or breastfeeding women
- Inability to give informed consent
Trial locations and contacts
1 site in 1 country.
About this study
4L split dose PEG is the gold standard for bowel preparation, however it comes with poor tolerability and poor compliance. Combination of PEG with different agent is useful in reducing total volume, improving compliance and tolerance of patient.
The objective of this study is to demonstrate that combination bowel preparation, PEG plus SPMC solution, has similar efficacy and safety profile whereas with a better tolerance when compared to large volume PEG.
Read the detailed description
This is a prospective, randomized, single-center, single-blinded, non-inferiority trial.
Participants with out patient colonoscopy arranged will be included and randomized in a 1:1 ratio to receive either a split dose of 4L PEG + Electrolyte (Klean-prep® ) or 1L Klean-prep® plus 2 sachets SPMC (Picoprep®).
Trained endoscopists will be using the Boston Bowel Preparation Scale (BBPS) to assess the quality of bowel preparation. Patient would also rate the tolerance, compliance and adverse effect by filling the questionnaire before the colonoscopy.
- Conditions
- Bowel Preparation Solutions, Colonoscopy
- Being tested
- 4L Klean Prep®, 1L Klean prep® and 2 sachets Picoprep®
- Keywords
- Polyethylene glycol, Picoprep, Cathartics, Bowel preparation solution, Colonoscopy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
4L Klean Prep®Drug
Patients allocated to the control group shall mix two sachets of PEG in 2L water. At 6pm the evening before examination, they shall consume 250ml solution every 15mins, and finish in 2hours. At 7am the day of examination, drink another 2L Klean-prep in 2 hours.
1L Klean prep® and 2 sachets Picoprep®Drug
Patients allocated to the study group shall mix each sachet of Picoprep® in 150ml warm water. The patient shall take the 1st dose at 4pm the day before procedure followed by at least five 250ml drinks of clear fluid before the next dose. The 2nd dose shall be taken approximately 6hrs later and followed by at least three 250ml drinks of clear fluid before bed. On 7am the day of procedure, they shall take 1L PEG in 1 hour.
| Study group | Role | What they receive |
|---|---|---|
| 4L Klean Prep® | Active comparator | Drug: 59g polyethylene glycol, 5.685g Na sulphate, 1.685g Na bicarbonate, 1.465g NaCl, 0.7425g KCl and aspartame 0.0494g Receives: Drug: 4L Klean Prep® |
| 1L Klean prep® and 2 sachets Picoprep® | Experimental | Drug: 59g polyethylene glycol, 5.685g Na sulphate, 1.685g Na bicarbonate, 1.465g NaCl, 0.7425g KCl, aspartame 0.0494g, sodium picosulfate 0.01g, magnesium oxide 3.5g, citric acid 12.0g Receives: Drug: 1L Klean prep® and 2 sachets Picoprep® |
What is being measured
The primary outcome is the main question the study is designed to answer.
Boston Bowel Preparation Score (BBPS)
Adequate bowel preparation is defined as a total BPPS score >/= 6 in which all three segments had score >/=2
Measured: Up to 24 weeks
Secondary outcomes (4)
Patient tolerability to bowel preparation using Likert scale
Patient are requested to fill in questionnaire on the day of colonoscopy. Candidate are asked to rate the frequency of complications between 'none', 'mild', 'moderate' and 'severe'. 'None' being the best outcome and 'severe' being the worst outcome.
Measured: Up to 24 weeks
Patient compliance towards bowel preparation
Proportion of patient able to complete the whole bowel preparation as instructed by protocol
Measured: Till the day of procedure
Proportion of patient requiring repeat colonoscopy
Proportion of incomplete colonoscopy due to inadequate bowel preparation Patient will be attended by physicians and blood taking will be arranged
Measured: Up to 24 weeks
Incidence of treatment related adverse events
Patient will be monitored after colonoscopy for any complications
Measured: Up to 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2020
- Study start7 Dec 2020
- Primary completion31 Dec 2022
- Study completion31 Dec 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bowel Preparation SolutionsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 158 participants (actual)
Sponsor and investigators
- Lead sponsor
- Queen Elizabeth Hospital, Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tso Yau Kan, Queen Elizabeth Hospital, Hong Kong
- Investigators
- Yau Kan Tso, Principal investigator, Queen Elizabeth Hospital, Hospital Authority
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04474002
- Sponsor's protocol ID
- PICO-PEG trial
- Status last verified
- Aug 2025
- First submitted
- 12 Jul 2020
- Last updated
- 26 Aug 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy, Tolerance and Safety of Split Dose Bowel Preparation for Colonoscopy: 4L Polyethylene Glycol (PEG) Versus 1L Polyethylene Glycol Plus Sodium Picosulfate-magnesium Citrate (SPMC)
- ClinicalTrials.gov ID
- NCT04474002
- Acronym / sponsor ID
- PICO-PEG trial
- Conditions
- Bowel Preparation Solutions, Colonoscopy
- Keywords
- Polyethylene glycol, Picoprep, Cathartics, Bowel preparation solution, Colonoscopy
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 158 participants (actual)
- Lead sponsor
- Queen Elizabeth Hospital, Hong KongUniversity, hospital or other
- Study start
- 7 Dec 2020 (actual)
- Primary completion
- 31 Dec 2022 (actual)
- Study completion
- 31 Dec 2022 (actual)
- First posted
- 16 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
4L split dose PEG is the gold standard for bowel preparation, however it comes with poor tolerability and poor compliance. Combination of PEG with different agent is useful in reducing total volume, improving compliance and tolerance of patient.
The objective of this study is to demonstrate that combination bowel preparation, PEG plus SPMC solution, has similar efficacy and safety profile whereas with a better tolerance when compared to large volume PEG.
Detailed description
This is a prospective, randomized, single-center, single-blinded, non-inferiority trial.
Participants with out patient colonoscopy arranged will be included and randomized in a 1:1 ratio to receive either a split dose of 4L PEG + Electrolyte (Klean-prep® ) or 1L Klean-prep® plus 2 sachets SPMC (Picoprep®).
Trained endoscopists will be using the Boston Bowel Preparation Scale (BBPS) to assess the quality of bowel preparation. Patient would also rate the tolerance, compliance and adverse effect by filling the questionnaire before the colonoscopy.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 4L Klean Prep® | Active comparator | Drug: 4L Klean Prep®Drug: 59g polyethylene glycol, 5.685g Na sulphate, 1.685g Na bicarbonate, 1.465g NaCl, 0.7425g KCl and aspartame 0.0494g |
| 1L Klean prep® and 2 sachets Picoprep® | Experimental | Drug: 1L Klean prep® and 2 sachets Picoprep®Drug: 59g polyethylene glycol, 5.685g Na sulphate, 1.685g Na bicarbonate, 1.465g NaCl, 0.7425g KCl, aspartame 0.0494g, sodium picosulfate 0.01g, magnesium oxide 3.5g, citric acid 12.0g |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patient who mentally capable to consent for participating the trial
- 18 - 65 years old
- Scheduled for 1st colonoscopy
- Elective outpatient colonoscopy
Key exclusion criteria (10 listed)
- Prior colorectal or abdominal-pelvic surgery
- Inflammatory bowel disease
- Active bowel condition eg intestinal obstruction
- Gastrointestinal disorders eg active ulcer, gastric outlet obstruction, gastroparesis and hypomotility syndrome
- Recent myocardial infarction, congestive heart failure, uncontrolled hypertension
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 4L Klean Prep®Patients allocated to the control group shall mix two sachets of PEG in 2L water. At 6pm the evening before examination, they shall consume 250ml solution every 15mins, and finish in 2hours. At 7am the day of examination, drink another 2L Klean-prep in 2 hours. | Drug | 4L Klean Prep® |
| 1L Klean prep® and 2 sachets Picoprep®Patients allocated to the study group shall mix each sachet of Picoprep® in 150ml warm water. The patient shall take the 1st dose at 4pm the day before procedure followed by at least five 250ml drinks of clear fluid before the next dose. The 2nd dose shall be taken approximately 6hrs later and followed by at least three 250ml drinks of clear fluid before bed. On 7am the day of procedure, they shall take 1L PEG in 1 hour. | Drug | 1L Klean prep® and 2 sachets Picoprep® |
Primary outcome
Boston Bowel Preparation Score (BBPS)
Time frame: Up to 24 weeks
Adequate bowel preparation is defined as a total BPPS score >/= 6 in which all three segments had score >/=2
4 secondary outcomes
Patient tolerability to bowel preparation using Likert scale
Time frame: Up to 24 weeks
Patient compliance towards bowel preparation
Time frame: Till the day of procedure
Proportion of patient requiring repeat colonoscopy
Time frame: Up to 24 weeks
Incidence of treatment related adverse events
Time frame: Up to 24 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Aug 2025.
- Individual participant dataSharing planned: No
Related trials for Bowel Preparation Solutions
Recruiting
Electrolyte Beverage Combined With Polyethylene Glycol for Colonoscopy Bowel Preparation
Colonoscopy, Bowel Preparation Solutions
Not yet recruiting
App-Based Education and Low-Residue Diet for Colonoscopy Preparation
Bowel Preparation Solution
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Yau Kan Tso principal investigator
Queen Elizabeth Hospital, Hospital Authority
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing 4L Klean Prep® and 1L Klean prep® and 2 sachets Picoprep® in people with Bowel Preparation Solutions and Colonoscopy, run by Queen Elizabeth Hospital, Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Boston Bowel Preparation Score (BBPS) (time frame: Up to 24 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Aug 2025.