Sounds familiar!
I too suffer with predominently IBS C, although it can change sometimes from day to day.
After trying for years to get help from doctors, I have settled on a more natural approach. I drink about 50 ounces of water a day. I take an herbal supplement which keeps moisture in the bowel and helps to keep things moving. I stay away from problem foods like white rice, bananas, pasta, CORN, cheese, etc. I used to take a stool softener, which I found helpful for a period of time.
Others have had success with Miralax. My understanding is that it is different from other laxatives in that is doesn't have the stimulant that causes the pain and spasm like most do. I have also found Magnesium Citrate extremely helpful when I get really backed up. It's a flavored liquid that works quickly and does not cause pain.
Hope that helps!