My 79 year old dad was diagonised with prostrate cancer last year in May, and only 6 days ago that is when they started with treatment. Since he was diagnosed last year he is still walking around with a catheter. They are doing a radiation treatment, and today he has started having a running tummy. Can someone who has been through this kind of treatment please advise what is the best diet to follow, what one can do. I know the doctor said it is part of the side effects but this is worrying. Unfortunately today he is weary of what he eats and scared because he is worried that he will have to run to the toilet. My mum who is also having her own health problems with the heart is so worried as well.