Hi Shelly,
Sorry to hear you are going through this. Unfortunately, after having major abdominal surgery, there can be internal scarring which could lead to painful intercourse. However, if you have not yet had a gyno exam, you should go for one, as there are many reasons for this problem, many of which can be very simply treated.
You should check out the Women's Health and Pregnancy forum on this site; I believe there is plenty of information on this topic there.
Good luck!