Hi! I tried it for 2 or 3 months and I can't say anything conclusive about it. In general I was doing better with all the different probiotics, I'm sure, but not sure definitively with this brand. However, VSL3 has some of the best studies out there specifically for UC: something like 50-70% remission or at least a major improvement. What I remember is that the duration was 2-3 months and the dose was about double the amount they say to take on their website (3 trillion microbes or 8 packets, if I recall). I think the "medical food" form of this is basically this high in number, but the price is about the same as getting the equivalent of the OTC version, if I recall. I could probably dig up the abstract, if you like. It is also good to supplement with a good prebiotic, which helps the good bacteria to grow and the form is usually soluble fiber (FOS, inulin, pectin, etc).
The gas is normal as your body adjusts to the new microbial balance. I know it is expensive, but I did talk with my flexible spending provider and they said I could write it off if I got a note from my doctor saying it was needed. I'd love to know the boundries of that! There are a lot of supplements I would enjoy tax free.