Look at my IGRT path - I posted day by day. Fatigue, loose bowels, increased incontinence are all expected side-effects.
There is always the possibility of much more severe problems - you might have noticed David's posts (Purgatory). If there is any mis-direction of the radiation, rectal and bladder damage are possible. I was told that the more serious side effects, if they were to happen, might not show up until several years after treatment.
So far (at 6 months after), I still have significant fatigue, a more frequent bowel than I would like, and my incontinence is now worse than it was 4 months after DaVinci surgery. Nothing to write home about.
My IGRT journey (2010) - www.healingwell.com/community/default.aspx?f=35&m=1756808