Diarrhea or constipation
In prostate cancer, it is common to experience changes in bowel habits, including diarrhea and constipation. There are other bowel symptoms associated with prostate cancer, including bowel incontinence and passing blood in the stools. There are plenty of explanations to these bowel changes, including that prostate cancer is likely to pressure upon certain spinal nerves, causing a disruption in the normal behavior of the digestive tract.
In other cases, inflammatory substances are responsible for a chemical reaction in the large intestine, causing accelerated bowel movements. It may also result from cancer therapy, in which case it is likely to be a temporary situation that resolves after cancer therapy is done with.