Mild case of UC but gas \ flatulence problems

I'm a 74 year old male in reasonably good health. My very mild case of UC is under control for a while now - rarely I see blood after a BM, but I'm pretty sure that's due to a hemmoroid - my stools are usually well-formed - no cramping. BUT, I do seem to have a lot of flatulence - A LOT - it's very annoying. I'm not incontinent, but the gas must also be passing some "debris" because I see brown stains and "skid marks" on my underwear - I wipe thoroughly after a morning BM, often using a water-based wipe. I take 6 500mg sulfasalazine each day. I also take probiotics, thinking that they'll be god for my "gut health", which will hopefully help the UC - I've asked my doctor, but he doesn't seem to have strong feelings either way about the probiotics. I also take wheat dextrin fiber each day. I have read that the wheat dextrin fiber is often responsible for gas \ flatulence. I tried the psycillium husk fiber (supposed to be less likely to cause gas) but the jellied consistency was uncomfortable. I'd REALLY like to reduce \ eliminate the gas - any suggestions? Thanks in advance . . . .