I use Activia and and sometime take probiotics. I have severe IBS and they really don't do much for mine. The only time that I've noticed a real difference is if I take antibiotics and then it's a must to take a good probiotic.
The only thing that has been helpful to me is Lotronex. It was a God-send, but I had severe diarrhea prevalent IBS-- however, now I seem to be cycling. I just started Etrafon for stomach spasms, vomiting, and recurrent diarrhea. But hopefully, yours won't get that bad.
I have found too that diet can be a trigger. Alcohol is a no-no for me, and if I drink, I will pay the next day, as I can't get off the toilet. Also, if I eat out, I can barely make it home, especially if there is a bunch of MSG in the food.
I have tried all kinds of diets though. You'll know though when you are having good and bad days. Maybe keeping a food journal will help identify trigger foods.