A Randomized Controlled Trial to Investigate the Role of Low or High 'Fibre' Diets in Patients Undergoing Pelvic Radiotherapy - The Fibre Study

OBJECTIVES:

Primary

• To compare the efficacy of a high- vs low-fiber intervention in preventing bowel toxicity in patients receiving radical pelvic radiotherapy treatment for gynecological, urological (bladder), colorectal, or anal malignancy.
• To compare whether a high- or low-fiber intervention has any beneficial effect over no intervention (i.e., ad-libitum fiber consumption).
• To examine the effect of a low- or high-fiber diet on gastrointestinal symptoms, measured using the IBDQ-B and Bristol Stool Chart, in patients receiving radical radiotherapy for pelvic malignancies.
• To minimize any potential risk associated with change in fiber intake by using a controlled and gradual dietary-based intervention combined with dietetic advice.

Secondary

• To examine the relationship between volume of irradiated bowel and onset of gastrointestinal symptoms as measured by the Bristol Stool Chart.
• To measure percentage compliance with fiber prescription through validated dietetic techniques including the 7-day Food Diary using household measures and the 24-hour recall.