Efficacy, Safety and Tolerability of Eziclen®/Izinova® Versus Klean-prep® on Bowel Cleansing in Adolescents Undergoing Colonoscopy

Inclusion Criteria: * Provision of signed informed consent form to participate in the study obtained from the adolescent's parent(s)/ legal representative and a signed assent form from the adolescent according to local law * Male or female subjects between 12 to 17 years of age (inclusive) * Body weight more than 40 kg * Female of childbearing potential must have a negative pregnancy test * If female, and of child-bearing potential, subject must use an acceptable form of birth control (hormonal birth control, intrauterine device (IUD), double-barrier method, or depot contraceptive) * Routinely accepted indication for undergoing colonoscopy, including but not limited to polyposis coli diagnosis or surveillance, gastrointestinal bleeding, unexplained diarrhoea or constipation, surveillance of inflammatory bowel disease or confirmation of mucosal healing, abdominal pain, abnormal endosonography or manometry, anaemia of unknown aetiology, cancer surveillance * In the investigator's judgment, the parent(s)/legal representative are/is mentally competent to provide informed consent for the subject to participate in the study * In the investigator's judgement, subject is able and willing to follow study procedures including drug administration and response to questionnaires Exclusion Criteria: * Subject with known or suspected ileus, gastrointestinal obstruction, gastric retention (gastroparesis), rectal impaction, toxic colitis, severe ulcerative colitis or toxic megacolon, advanced carcinoma, swallowing disorders * Subject with known or suspected inflammatory bowel disease (Crohn's disease, ulcerative colitis) in moderate to severe active phase defined by Paediatric Crohn's Disease Activity Index (PCDAI) \>30 or Paediatric Ulcerative Colitis Index (PUCAI) \>34 * Subject with bowel perforation or increased risk of bowel perforation, including connective tissue disorders or recent bowel surgery * Subject with previous significant gastrointestinal surgery (e.g. colostomy, colectomy, gastric bypass, stomach stapling) * Subject with uncontrolled pre-existing electrolyte abnormalities, or with electrolyte abnormalities based on Visit 1 laboratory results such as hypernatremia, hyponatremia, hyperphosphatemia, hypokalaemia, hypocalcaemia, uncorrected dehydration, or secondary to the use of medications such as diuretics or angiotensin converting enzyme inhibitors judged clinically significant by the investigator * Subject with a prior history or current condition of severe renal (estimated glomerular filtration rate (GFR) less than 30 mL/min/1.73 m\^2 as calculated by using the Schwartz bedside equation\* \[Schwartz et al, 2009\]\*\*), liver (ascites, Child-Pugh C), cardiac insufficiency (including congestive heart failure all grades) or hyperuricemia \*The estimated GFR will be calculated in patients with elevated creatinine at baseline \*\*Schwartz GJ and Work DF. Measurement and Estimation of GFR in Children and Adolescents. Clin J Am Soc Nephrol. 2009; 4: 1832-1843 * Female subject who is pregnant or lactating * Subject who has participated in another investigational drug treatment within the last 90 days before the first study visit * Subject with phenylketonuria * Subject with history of asthma or hypersensitivity to any ingredient of either drug product * Subject for whom intake of substances likely to affect gastrointestinal motility or urinary flow rate is required * Subject with requirement to take any other oral medication within 3 hours of starting the bowel preparation, as this may impact medication absorption * Subject with tendency for nausea and/or vomiting * Subject with impaired consciousness that predisposes them to pulmonary aspiration or who have known swallowing disorders * Subject with history of major medical/psychiatric conditions that, in the judgment of the investigator, would compromise safety in the study * Subject with mental or psychiatric condition rendering the subject unable to understand the nature, scope and possible consequences of the study, and/or evidence of an uncooperative attitude * Subject with a condition that, in the opinion of the investigator, might increase the risk to the subject or decrease the chance of obtaining satisfactory data needed to achieve the objectives of the study * Subject who has previous enrolment in this study or concomitant enrolment in other clinical studies