IntroductionColonoscopy plays important roles in bowel cancer screening and treatment. Poor bowel preparation occurs in 20–25% of colonoscopies. This negatively impacts adenoma and sessile serrated lesion detection rates, procedural time, requirement for repeat colonoscopies, healthcare costs and likelihood of patient withdrawal from screening programmes. It is unclear whether a combination of multimedia modalities can improve bowel preparation quality, adenoma detection rates and patient-reported measures in those undergoing colonoscopy assessment.MethodsThe DIGICLEAN trial is a prospective, parallel, multicentre, colonoscopist-blinded, randomised controlled trial. The trial will enrol 1294 participants aged 45 years and older who are indicated for a colonoscopy as an outpatient with a positive faecal occult blood test, iron deficiency anaemia or rectal bleeding. Participants will be randomised into the interventional arm, where bowel preparation instructions are delivered via a web-based application which uses scheduled short messaging service, regular patient survey assessment, email and videos; or the control arm, where routine standard written, verbal or emailed instructions are administered. The web-based application will assess patient-reported bloating, constipation and dietary adherence leading up to the colonoscopy. Depending on patient responses, additional aperients may be encouraged digitally in the interventional arm with same instructions made available in written format for the control arm. Patient-reported measures will be collected in both arms the day after the procedure using the validated Newcastle ENDOPREM questionnaire. In some sites, participants will undergo digital pre-anaesthetic screening as well. The co-primary endpoints are the adenoma detection rates and patient-reported measures taken after the colonoscopy.Ethics and disseminationEthics approval for this study was obtained from the Western Sydney Local Health District Human Research Ethics Committee (2022/ETH00059). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals.Trial registration numberACTRN12622000747729.