Is this normal for IBS and how can I fix the problem?

I'm 26 and have had IBS with constipation ever since the birth of my last child 1 1/2 yrs ago. My symptoms tend to be worse during my period, and my period just ended yesterday. I've been EXTREMELY gassy for the past 3 days, but have not been able to have a bowel movement. Well, today, I had a bowel movement early this morning. It was normal in appearance, but I got zero relief after it. Later on, I tried to go to the bathroom again, and it was able to get out a little bit of softer bm. Tonight, I tried again (since I still don't feel any relief), and I got out a couple of normal pieces of bm. My issue is that the more that I get out, the worse I feel. It almost feels as though my intestines are bruised. If I lay down, my stomach is nowhere near as sore, but the minute I stand up and attempt to do anything, the soreness returns. Is this normal for IBS with contipation and if so, what can I do to relieve my symptoms?