Hi Kelso, I have gone through 20 days of RT. You will be told to drink a certain amount of water about 20 mins before RT. I only had one episode of a full bowel, which they tell you during the session, when you then have to have an enema , which only takes a few minutes, then you return for the RT. They could give you some enemas for future problems if you feel you need to take one. Hope all goes well. I had a PSA of 29 before RT, I had test a week or so later and it of .02.