If you have SIBO I strongly recommend that you take prebiotics like Galactomune 16-18 hours after taking probiotics and/or fermented veggies. It is best to take probiotics first thing in morning and prebiotics right before you go to bed. This way, the probiotics will be in the colon when the prebiotics arrive to feed them.
Oats do not contain gluten. Only wheat, barley and rye contain gluten. So why do some oat products say "gluten free" on the packaging? Part marketing and partly because these manufacturers process all sorts of grains in the same factory. If they aren't careful, some gluten grain dust can drift over to where the oats are and contaminate them with tiny amounts of gluten. Bob's Red Mill goes to the trouble of processing the oat bran in a separate room to prevent this from happening. That is why they label it as gluten free even though oats contain no gluten.
When I was doing enemas I was using something called Cabbage Rejuvelac as my enema fluid. It is rich in natural probiotic bacteria like Lactobacillus Plantarum. It also is slightly acidic and helps cause bowel movement compared to plain water or salt water. Here are posts on how to make it and how to use it: