As we have mentioned, prostate cancer features an inflammatory condition in the prostate and all the surrounding tissues, especially the bladder and urethra. However, the rectum is right behind the prostate tissue and would be affected by the inflammation as well.
The inflamed mucosa of the rectum becomes more sensitive to pain as a result of the interaction between the molecular markers of inflammation and the nerve terminals. These nerve terminals are there to detect an insult to the tissue and send the pain signal to the brain. Inflammation releases a series of molecules that increase the sensitivity of nerve terminals, making them especially sensitive to pain.
Patients do not necessarily report rectal pain. Some patients do not have any rectal symptoms; others would have a sensation of heavyweight, a lump in the rectum, or just a general sense of discomfort. In some cases, patients would have additional rectal symptoms, such as rectal bleeding.