I think I know what you're talking about. Something like that happens to me almost all the time when I need to go. I always thought of it as something that kinda alerts you that you need to go to the bathroom. I'm pretty sure its nothing unless you're in unbearable pain.
IBS does seem to stay with you, but there are ways to make it alittle more pleasant. For me, I eat yogurt (Activia works nice if you're constipated) as does my dad. We both tend to get constipated alot, and Activia has helped keep me regular. Any other yogurt works well too, but Activia gives you faster results. Eating one a day works fine for me. Also, if you havent done so, increase your fluid intake. Lots of water helps. Sodas, alcohol, and some other drinks can cause you to be dehydrated, making your stools harder to pass. Another helper is Fiber suppliments/drinks.
Hope these help you. :)