This patient support community is for discussions relating to advanced or metastatic prostate cancer, biopsy, bone scan, blood in urine or semen, benign prostatic hyperplasia (BPH), CT scan, cystoscopy, erectile dysfunction (ED), hormone therapy, incontinence, pain (abdomen, lower back or hip), PSA test, prostatitis, radiation therapy, rectal exam, recurrent cancer, screening, staging (tumor size, metastasis), transrectal ultrasound, watchful waiting, and urinary difficulty, burning, or urgency (leaking).
As for colon cancer, some signs could be blood in the stool or an overall change in bowel habits. Do a google search and you'll find a ton of info.
The prostate lies along the passage of urine. It secretes a fluid with the semen during intercourse. The colon is the large bowel, which processes feces.
Knowing these things- the symptoms are pretty simple to guess. Blood in the urine may mean prostate enlargement or cancer (among other considerations), and obstruction with flow or any other problems voiding would mean evaluation of the prostate. Blood in the feces or changes in bowel habits will raise an evaluation of the bowels.