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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Comparing to see if picosalax in combination with low residue diet is as good for bowel cleanliness and better tolerated than current bowel preparations used for morning colonoscopies.
Scientific title
A Single-blind, randomised non inferiority study of the effectiveness and tolerability of picosalax and low residue diet compared to standard bowel preparation prior to morning colonoscopy
Secondary ID [1] 282064 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
effectiveness of bowel preparation 288550 0
tolerability of bowel preparation 288551 0
Condition category
Condition code
Oral and Gastrointestinal 288880 288880 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Study type
Description of intervention(s) / exposure
Picosalax bowel preparation in combination to low residue diet

Picosalax Two sachets, each to be mixed in 250ml of water
*One to be taken 9pm the day prior to the colonoscopy
*One to be taken 4am on the day of the colonoscopy

The low residue diet is to start 2 days prior to the colonoscopy and cease when bowel preparation starts
* Examples include : *Milk (regular, low fat, skim), water, lemonade, soda or mineral water, clear (not coloured) Gatorade or other sports drinks
*Regular white bread/toast, rice bubbles, white rice, regular pasta, potatoes (peeled), rice noodles, plain rice crackers, white flour, sugar
*Eggs, Chicken breast (no skin), white fish fillet (no skin)
*Plain cream cheese, cheddar cheese, ricotta, fetta, cottage, parmesan or mozzarella cheese, white sauce
*White coloured yoghurt (no added fruit or inulin), mayonnaise, cream, sour cream, butter and margarine, oil for cooking
*White chocolate, vanilla ice cream, lemonade icypole, clear jelly, custard, “milk bottles”(confectionery

Adherence will be assessed through a food diary that the patient fills up during the two days prior to the colonoscopy
Intervention code [1] 286662 0
Early detection / Screening
Comparator / control treatment
Current standard bowel preparation ie. clear fluids diet with PrepKit C

Day before the procedure, the patient is only to have clear fluids after a light breakfast. Examples include :
* Clear broth or Bonox
Clear fruit juice without pulp or seeds (eg Apple juice)
* Coffee or tea without milk
* Gatorade, Sportsplus, Lucozade, or Gastrolyte
* Soft drinks
* Fruit flavoured cordials
* Plain jelly without added fruits or toppings
(avoid red and purple coloured drinks/jellies)

PrepKitC contains two sachets of picoprep and one sachet of glycoprep
5pm - Picoprep one sachet with 250ml of water
6pm One sachet of Glycoprep in 1L of water
7pm One sachet of Picoprep with 250ml of water

Patients are then to fast from midnight
Control group

Primary outcome [1] 289010 0
Quality of bowel cleanliness- this is assessed via the Ottawa bowel cleanliness scale which has 2 components:
1. Three sections of the colon - the degree of washing and suctioning required to obtained a clear mucosa with a score allocated
2. The total amount of fluid present in the entire bowel

The 2 components are then added to determine the final score
A score of 5 or less is deemed successful.
A score of 6 or more is deemed unsuccessful.
Timepoint [1] 289010 0
During the Colonoscopy
Secondary outcome [1] 301555 0
Patient tolerance, acceptance and compliance with the study bowel preparation in comparison to current bowel preparations used- assessed via a questionnaire
Timepoint [1] 301555 0
By the scheduled colonoscopy date
Secondary outcome [2] 301556 0
Caecal and terminal ileal intubation rates
Timepoint [2] 301556 0
At the colonoscopy
Secondary outcome [3] 301557 0
time taken to complete the procedure
Timepoint [3] 301557 0
End of the colonoscopy
Secondary outcome [4] 301558 0
Polyp to adenoma detection rate ratios.
The total polyp numbers for each patient is determined by the end of the procedure.
The removed polyps are then examined and proportion of adenomatous polyps are then determined by the pathologist.
A ratio is then calculated from both these values.
Timepoint [4] 301558 0
When histology available- generally 2 to 4 weeks from the procedure date
Secondary outcome [5] 301559 0
A history of constipation, laxative use or opoid analgesia usage affects the quality of bowel preparation- this is determined through a patient questionnaire completed and handed over on the day of the colonoscopy
Timepoint [5] 301559 0
Day of the colonoscopy

Key inclusion criteria
Consenting adult patients (aged 18 years and greater) undergoing outpatient colonoscopy for clinically accepted indications.

Clinically accepted indications generally include but are not restricted to iron deficiency anaemia, surveillance of bowel polyps, colorectal cancer screening, assessment of symptoms such as abdominal pain, diarrhoea and constipation, assessment or investigation of inflammatory bowel disease.
Minimum age
18 Years
Maximum age
99 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion criteria are conditions generally considered as exclusions to colonoscopy in normal clinical practice.

They are suspected bowel perforation, gastric outlet obstruction, toxic megacolon, severe colitis, and pregnancy or lactation.

For additional safety, will also exclude patients with the relative contraindications of significant renal failure (eGFR<30) significant heart failure (New York Heart Association Class III or IV).

Prep-Kit C is contraindicated in individuals with phenylketonuria, due to the presence of aspartame and patients with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency given it contains ascorbic acid (vitamin C) which is an oxidant. Any person with a known hypersensitivity to a constituent of Picoprep, Glycoprep or Picosalax will also be excluded.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed

Patients will be invited to participate in this study from outpatient gastroenterology clinics at the Alfred Hospital and inpatient wards of the Alfred hospital. We will only be recruiting people to this study who have been advised to have a colonoscopy for clinically accepted reasons. We may also contact patients who have already been booked for elective outpatient colonoscopy at the Alfred Hospital but are awaiting their procedure.

Given that patients may wait for a period of weeks to many months for their colonoscopy after the time of booking (depending on the urgency of the indication), a number of potential participants will already exist on the waiting list at the Alfred Hospital when recruitment begins. We will recruit patients already waiting for elective outpatient colonoscopy who have not yet been invited to participate in the trial and have not received the standard Alfred instructions regarding bowel preparation for their colonoscopy. The research nurse or an investigator may contact the patient by phone to invite them to participate, provide a verbal explanation of the trial, the benefits and risks of involvement and then if they are interested, mail them the study information sheet and consent form should they wish to participate. They will be informed that a decision not to be involved in the study will not influence their treatment
or the timing of their procedure
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation

Patients will be randomly allocated to one of the dietary regimens on a 1:1 basis.
Randomisation will occur at the time a colonoscopy is booked to a specific date allocated to a morning list. The sealed envelope will be mailed along with other standard instructions about the time of their procedure. The bookings clerk will record the patient’s hospital ‘UR’ number with their study reference number on a password protected database at that time.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Sample size calculated assuming a 75% success rate with clear fluids based on prior research and a non inferiority margin of 15%.
Approximately 104 patients are required in each group. Adding 20% to account for drop outs, 125 will be studied in each group (250 in total)

An intent-to-treat analysis will be used to assess the primary outcome. The percentage of success will be assessed in each treatment group and the 95% confidence interval for the difference in success rates will be determined. Non-inferiority of the low-residue diet with Picosalax regimen will be established if the lower confidence limit for the difference in effect turns out to lie above -15%. An interim analysis will be performed looking at the primary end-point after 50% of recruitment.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 786 0
The Alfred - Prahran
Recruitment postcode(s) [1] 6596 0
3181 - Prahran

Funding & Sponsors
Funding source category [1] 286928 0
Name [1] 286928 0
Alfred Hospital
Address [1] 286928 0
55 Commercial Road Prahran Vic 3181
Country [1] 286928 0
Primary sponsor type
Alfred Hospital
55 Commercial Road Prahran Vic 3181
Secondary sponsor category [1] 285716 0
Name [1] 285716 0
Address [1] 285716 0
Country [1] 285716 0

Ethics approval
Ethics application status
Ethics committee name [1] 289176 0
Alfred Hospital Ethics Committee
Ethics committee address [1] 289176 0
55 COmmercial Road Melbourne Prahran Vic 3181 PO BOx 315
Ethics committee country [1] 289176 0
Date submitted for ethics approval [1] 289176 0
Approval date [1] 289176 0
Ethics approval number [1] 289176 0

Brief summary
Primary purpose of the study is to examine if a low volume bowel preparation in conjunction with a white diet will have the same cleansing effect as current bowel preparations.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 38282 0
A/Prof Gregor Brown
Address 38282 0
The Alfred Hospital
Level 4 Department of Gastroenterology
55 Commercial Road Prahran Vic 3181
Country 38282 0
Phone 38282 0
Fax 38282 0
Email 38282 0
Contact person for public queries
Name 38283 0
Dr Jonathan Yong Chiang TAN
Address 38283 0
The Alfred Hospital
Level 4 Department of Gastroenterology
55 Commercial Road Prahran Vic 3181
Country 38283 0
Phone 38283 0
Fax 38283 0
Email 38283 0
Contact person for scientific queries
Name 38284 0
Dr Jonathan Yong Chiang TAN
Address 38284 0
The Alfred Hospital
Level 4 Department of Gastroenterology
55 Commercial Road Prahran Vic 3181
Country 38284 0
Phone 38284 0
Fax 38284 0
Email 38284 0

No information has been provided regarding IPD availability
Summary results
No Results