I'm sorry to hear that.
I have IBS as well and for most part I don't have to many issues with anal and it. But there are times when I do. When that happens I just don't do anal. But in your case it sounds like it happens all the time. But since it's recently developed for you it may get easier in time. What I mean is when I first developed IBS myself it was horrible. I always hurt. I know back then I wouldn't have been able to do anal at all. Even when my IBS was being "good." But once I figured out the right diet for me, removed all the triggers from my diet, etc, etc. overtime my IBS got better. Best advice I can give is read up as much as you can on IBS, a lot of talking with your DR, and lots and lots of trail and error (with the guidance of your DR of course). Once you can get IBS under as much control as you can then you may be able to enjoy anal.