I agree with lvoss, tread lightly when starting satin balls, they are very rich and nutrient dense and if he truly does have a stomach upset, he more then likely will actually get sick from the richness in the balls. They are good to give a dog as a supplement with regular food, but should not be given as sole food or to a dog with stomach issues. That being said, once his stomach gets better you could easily add some with his regular food and see how he does. I freeze mine individually so I can pull one or more out when I feel my skinny boys need something extra (I do serve mine raw, but they can just as easily be cooked).
I use fortiflora if we have some issues going on, but daily my dogs all get "plant enzymes and probiotics" by Animal Essentials..it is an all natural diestive aid..there are several different brands/versions out there.
I saw in an earlier post that you free feed, I highly recommend for you to change that to regular twice(or once if that would work better) a day feedings, so you can see exactly how much he consumes. It will take a few days for your dogs to get used to it, but tehy will catch on rather quickly. It is healthier for them to eat and then get hungry in between feedings as suppose to grazing all day, at least that is my opinion.
Good luck and keep us posted.