PROstate CAncer Radiotherapy - Bowel Quality of Life (PROCAR-BQ)

Inclusion Criteria: * Men with PCa which are candidate for pelvic radiotherapy (RT) with or without previous surgery, with or without concomitant hormonotherapy (HT), Performance status (PS) 0-2 (all patient able to undergo RT treatment), of all age, elderly included. Exclusion Criteria: * Previous RT to the pelvis * Diagnosed Inflammatory Bowel Disease (IBD), celiac disease * Severe GI symptoms before the beginning of RT (Grade \> 2 according to CTCAE grading system) * Obvious cognitive impairment, * Inability to understand French/English and no contact person able to accompany and translate.