Just like with RSD everyone reacts differently to different treatments for IBS so please try different things to see what works for you. For instance taking Imodium is ok for those who only swing to the Diarrhea side but not if you either swing between both (this is what I have had for the last 20 years) or mainly get constipated. Personally I like benefiber the best and will take it twice daily if I am having a flare up. I also avoid all the trigger foods and alcohol. I can't give up coffee but limit it. I also eat a bland diet until it passes (I had to do this for 6 months once after a pain med did me in). There are also many probiotics on the market just hit the digestive aisle. I like the pearls best and ideally would take it everyday but I am lazy and only dose when I am either very stressed or having a flare. At my last doctor visit she mentioned Flax seed as something that has been seen as helpful. You just sprinkle it on food and it is kind of yummy. That has seemed to help and I take travel packets with me when I go abroad. Unfortunately there isn't really a cure all but there are many products and supplements that help.

Of course many of the meds prescribed to treat the RSD also can trigger IBS symptoms so it is a bit of a balancing act.
Good luck!