My husband takes turmeric + black pepper + olive oil all made into a paste called "Golden paste". Also, no sugar, bread, low carbs, no meat, dairy etc.

I'd agree with what you wrote, it does seem that he is running out of things to eat.

Talk with your RO about possible medical treatment. Mine suggested immodium, even absent loose stools. I had the symptoms you're having, as well as "moving/transient" abdominal cramping that would come on within seconds, often move around the abdomen, then might stay around for hours or might subside within minutes. When this cramping got bad, I took a tablet of hyoscyamine (an anti-cholinergic that slows down the normal intestinal motion), which stopped the pain within minutes and lasted for hours.

In addition to the immodium, my RO mentioned other meds, both tablets and suppositories, that could be prescribed if my discomfort did not resolve.

Now, some 6+ months after treatment, I still have bowel urgency at times, but the cramping and tenesmus have drifted back into history.

I watched my diet for a while, staying away from foods that seemed to bother me. My RO said that they didn't have a standard list of what to eat or not eat, because it seems that people are so different in what bothers them. Try things in moderation. If they give you trouble, don't eat them for a few weeks. If they are OK, keep them on your diet list. I got pretty good at predicting what would be OK to eat, after a couple of weeks. It gradually gets better. I'm sorry, but I just can't get behind Annie's diet suggestions. The "golden paste" idea turns my stomach, and all the other restrictions make it seem like you should throw away the food and eat the boxes. I did fine with a carefully watched, pretty balanced diet. I don't eat fried foods and I don't add salt to anything. I also have maintained a low-fat diet for over 30 years. Maybe all that helped, but the paste. . . ugh!

As Andrew said, try to step back into your regularly scheduled life activities as soon as you can. I did push myself a bit -- never missed a day of work or a day at the gym. I feel fine now, so that plan worked for me.

Radiation can destroy your intestinal flora which helps your body in numerous ways. Probiotics is a good way to reestablish it.

The side effects of radiation treatment are very hard to predict..Some men have very few side-effects (when being treated for prostate cancer) while others suffer debilitating side-effects. Every treatment plan is different, dosage is different, the LINACS used to administer the radiation are different and the skill level of the team who develop and administer the radiation can vary considerably....That's why it's so important to choose the best RO you can find and hope he does his job well....Especially with SBRT...Mistakes here tend to be big mistakes that can cause major injury that are called "side effects"....

As others have mentioned, Metamusil is good as it softens hard stools and hardens soft stools.

I have a different opinion on taking probiotic when you still have the side effect. It may add more harm than good. You already have a irritating rectum, why stimulating it more with microorganisms. I will wait for your rectum lining healed or recovered. However, I am not a doctor, just my personal concern. I also had a SBRT with Dr. King a month ago. Then I had a minor rectal urgency 2 weeks after treatment. Some red mucus in stools for a week or so. Then it stopped and getting better in the past few days. I was thinking about taking probiotic myself too, but I will wait for few more weeks when all the side effect is gone. Just wait for my poor rectum back to normal again. BTW, I have asked Dr. King about the diet/food, he said no restriction, just try to avoid caffeine.

My thought was that by introducing healthy bacteria we could inhibit or eliminate the bad microorganisms which could cause problems. My question is will healthy bacteria flora survive or make it all the way to the rectum?

Like tennisplayer, I've been taking Florastor (prescription Saccharomyces boulardii lyo ) since an IBS Dx. five years ago, and it has worked very well.