Has anyone had diarrhea with radiation?

I’n not a surgeon but I do know anatomy. How can you totally avoid the bowel when it extends so far down in the abdomen?
It doesn’t seem that you are having a pinpoint SBRT (cyberknife) approach but more the conventional blanketing of the affected area, which comes with bowel repercussions.
Just my opinion, not medical advice.

It would be interesting to ask how exactly he is “avoiding the bowel and previously treated prostate bed.” VMAT is very accurate in that it can precisely hit an intended target. But, VMAT does use photons/x-rays; and by their physical nature, photons exhibit high entry-dose, scatter, and exit-dose. (See attached graphic from a webinar I attended a couple of years ago.) This inherent nature of photons can be reduced, but they will still have a GI side-effect (which you’re obviously experiencing).

Yes, diarrhea about 10 days after treatments started. Imodium worked very well and kept it under control. Good luck with your treatments.

Hi there. Even though my RO used SBRT (TrueBeam STX) for a five fraction course, he indicated that even with SpaceOar to protect the bowel diarrhea was a possibility espcially since they also advised a low fiber diet during treatment to keep the bowels "less active" or something to that effect. In any case, I did have some minor diarrhea which I addressed with Pepto Bismol or Imodium, and drinking a lot of water. After a month + since I finished treatment everything is back to normal. Best of luck to you.

I had 20 rounds of SBRT. While I didn't have diarrhea, there was radiation damage visible near the end of my digestive tract during my last coloniscopy (2 years after the radiation). I also took damage to the bottom of my bladder (confirmed by cystoscopy).

It's not just a matter of how accurate the radiation beam is, though SBRT is a big improvement over earlier lead-blanket approaches (with the narrow beam annd constant rotation, superficial burns to skin are now very rare, for example).

My radiation oncologist explained to me that the radiation introduced into the prostate continues to kill cells — cancerous or otherwise — for weeks after the treatments finish, so I wouldn't be surprised if it can spread out a bit from your prostate to surrounding organs (just a layperson's guess).

That can also be a good thing, because it might attack any undetected localised cancer spread (which surgery doesn't), but it can still create discomfort.

Great comment. Thanks for sharing.