Well my GP emailed me back after two weeks to tell me radiation damage to my bowels from radiotherapy is a known fact & can last many years after you’ve finished radio therapy…Deep joy nobody mentioned that to me at the time so I’m stuck with not venturing far from the toilet for years to come. 
Still cant find out what the other PSA blood tests were, My doc says get in touch with my oncologist at Christies to address these bowel/nerve pain in both feet & the PSA test issues.
I did that & my oncologist says I need to speak to my GP about them !!! I give up.