The purpose of the study is to assess the efficacy, safety and tolerability of PLENVU® by measuring its bowel cleansing success rate compared to sodium picosulfate in paediatric participants aged less than 18 years who are scheduled to undergo a colonoscopy. Colonoscopy is a crucial procedure that helps to diagnose and manage various gastrointestinal (GI) conditions in paediatric patients. An adequate level of bowel preparation and cleansing is essential for effective colonoscopy to allow proper visualisation of the bowel.

This is a multicentre, active-controlled study in which the participants will be randomised 1:1 into one of two treatment groups - PLENVU® or sodium picosulfate in a 2-day split dosing regimen. The study will include -

1. A Screening Period of up to 28 days (Day -28 to Day -1).
2. A Treatment Period (Day 1 to Day 2) - Participants will be randomised to receive either PLENVU® or sodium picosulfate. Participants will be admitted into the Clinical Research Unit (CRU) on Day 1 and will remain in the CRU for the duration of study intervention administration (Day 1 and Day 2) and colonoscopy (Day 2). Participants will be discharged on Day 2 following the colonoscopy and evaluation of colon cleansing.
3. A safety follow-up call or CRU visit (Day 9 ± 2 days).

Inclusion Criteria:

• Participants who require a colonoscopy.
• Must weigh a minimum of 10 kg, and participants aged 1 to < 4 years of age must be above the 10th percentile of weight for age.
• Must have a negative urine pregnancy test (or serum if a urine pregnancy test cannot be confirmed as negative [e.g. three ambiguous results]) within 24 hours before the first dose of study intervention.
• Must use a highly effective method of contraception (failure rate < 1% per year) from Day 1 and throughout the Safety Follow-up Period.
• Must not be breastfeeding.
• Participant is able to receive regular external feeding without breastfeeding.

Exclusion Criteria:

• Has a past history within last 12 months or current episode of severe constipation (requiring repeated use of laxatives/enema or physical intervention before resolution).
• Has known or suspected ileus, GI obstruction, gastric retention, bowel perforation, toxic colitis, ischaemic colitis, or megacolon.
• Has ongoing severe acute inflammatory bowel disease that contraindicates colonoscopy.
• Participant has history of significant GI surgeries.
• Has known glucose-6-phosphate dehydrogenase (G6PD) deficiency or phenylketonuria.
• Participant has a past history within the last 12 months or evidence of any ongoing clinically relevant electrocardiogram (ECG) abnormalities (e.g. arrhythmias).
• Has a history of uncontrolled hypertension.
• Participant has regularly used laxatives or colon motility altering drugs in the last month (i.e. more than two times per week) and/or has used one or more laxatives within 72 hours prior to administration of the preparation.
• Has known hypersensitivity or allergic reaction to PEG, ascorbic acid, sodium picosulfate, magnesium oxide, or any other component of the investigational product or comparator.
• Received or scheduled to receive any vaccines or devices within one week prior to first dose of study intervention.
• Has a significant neurological disorder or a past history of seizures (excluding simple febrile seizures) or is currently on medication lowering seizure threshold (e.g. tricyclic antidepressants) or has used seizure threshold lowering medication within 14 days prior to administration of the preparation.

The central reader colonoscopist will be blinded to the study intervention.