How long to wait for colonoscopy after treatment for prostate cancer?

Posted by merwether @merwether, Nov 6, 2025

I'm a few months overdue for colonoscopy. I had 6 weeks of Proton radiation treatment 18 months ago for prostate cancer. Any negative experiences for having colonoscopy following Proton radiation treatment for prostate cancer?
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jc76 | @jc76 | Nov 7, 2025

@merwether
When I was at same facility as you they (UFHPTI) they insisted I had a colonoscopy prior to radiation as they did not recommend them for 3 years after radiation (damage to colon).

Since I had my colonoscopy prior to radiation I was not scheduled for another for 5 years. Are you having issues that warrant having the colonoscopy or is it just a routine ongoing test? That would make a big difference in having one so close to radiation treatments.

Colleen Young, Connect Director | @colleenyoung | Nov 20, 2025

@merwether, did you discuss the timing of your colonoscopy with your radiation oncologist? What did you find out?

merwether | @merwether | Nov 21, 2025

My oncologist sent a letter to be shared with my gastroenterologist. The letter stated that the anterior rectal wall should not be biopsied because it may result in " chronic severe bleeding or major surgical intervention".
Since polyps have been found and removed from each of my previous three colonoscopies I plan to meet with my gastroenteroloist in advance to see if the risk is worth doing a colonoscopy at this point. I don't understand the purpose of undergoing a colonoscopy if the gastroenterologist is advised to not remove polyps if found but that's something I will discuss with him prior to undergoing procedure.
As always, thanks Colleen.