PURPOSE: A scoping literature review was conducted to identify gastrointestinal (GI) factors most likely to influence prostate motion during radiotherapy. We proffer that patient specific measurement of these GI factors could predict motion uncertainty during radiotherapy, facilitating personalised care by optimising treatment technique e.g., daily adaption or via bespoke patient pre-habilitation and preparation. METHODS: The scoping review was undertaken as per JBI guidelines. Searches were conducted across four databases: Ovid Medline®, EMBASE, CINAHL and EBSCO discovery. Articles written in English from 2010-present were included. Those pertaining to paediatrics, biological women exclusively, infectious and post-treatment GI morbidity and diet were excluded.Common GI factors impacting men were identified and related symptoms, incidence and measurement tools examined. Prevalence among persons with prostate cancer was explored and suitable assessment tools discussed. RESULTS: A preliminary search identified four prominent GI-factors: mental health, co-morbidity and medication, physical activity, and pelvic floor disorder. The scoping search found 3644 articles; 1646 were removed as duplicates. A further 1249 were excluded after title and abstract screening, 162 remained subsequent to full text review: 42 mental health, 53 co-morbidity and medication, 39 physical activity and 28 pelvic floor disorder.Six GI factors prevalent in the prostate cancer population and estimated most likely to influence prostate motion were identified: depression, anxiety, diabetes, obesity, low physical activity, and pelvic floor disorder. Reliable, quick, and easy to use tools are available to quantify these factors. CONCLUSION: A comprehensive GI factor assessment package suitable to implement into the radiotherapy clinic has been created. Unveiling these GI factors upfront will guide improved personalisation of radiotherapy.