I've had my jpouch for 9 years. I've only had pouchitis once. I take a probiotic every day, Risaquad. I don't think you need to invest in an expensive probiotic like VSL unless he was to have chronic PI. There are lots of probiotics out there to choose from and you will get hundreds of recommendations. As for kidney stones, yes dehydration can cause them. Remember that thousands of people get kidney stones and most of them have a colon. He will need to be careful to stay hydrated to prevent further stones but he could just be one of those who is prone to them. It's interesting that he is getting severe gas pains this far out from surgery. I recommend that he keep a food diary to see if he can chart what is bothering him. For me, in the early days, wheat was a huge problem so I eliminated it for about 6 weeks. I had to read labels carefully as wheat was in everything! Other foods that could trigger more gas are dairy, carbonation, legumes, etc. A good probiotic can reduce gas so another good reason to add one. When he is in pain have him walk! Lots of moving around will help to move the gas.
dx proctitis in 1987
dx UC in 1991, was stable until 1998
1998 started prednisone, asacol, pentasa, nortriptylene, ativan, 6MP, rowasa enemas and suppositories, hydrocortisone enemas, tried the SCD diet, being a vegetarian, omega 3s, flax, pranic healing, yoga, acupuncture, probiotics
2000 lost all my B-12 stores and became anemic
2001 opted for j-pouch surgery- now living life med-free