unsure if my pain is caused from damage from radiation damage

I had colorectal cancer 8 years ago. I underwent chemo, radiation, surgery, and then more chemo. I have had several ct scans, and blood work done to make sure the cancer hasnt returned. I have had pain in the left side where i now have a colostomy due to the cancer every since treatments. When they did my colostomy, which by the way is perminant, they also took out my appendix so as to prevent any complication in case of an appendisitis (appendicitis). Two years ago my gall bladder was filled with stones and it was removed. But i was sick for well over a year before they found that my gall bladder was the cause. Since then i have continued to experience pain in my abdomen, my lower back, my left and right sides. This pain can at times be so bad that my pain meds do not help and i begin throwing up excesivly. I end up having to go to the er where they usually treat me for dehydration, pain, and give me something to control my vomitting. As i said, i have had several test done..none of which detect cancer. The doctors can only guess that my pain is caused from scarred tissue due to intenal damage due to radiatio therapy and the surgery i had. Is there any way to find out for sure? They dont want to do exploritory surgery because they say it is too dangerous. I have been dealing with this pain for so long and it has affected every aspect of my having a normal life. I take pain meds on a regular basis to allow my pain to come down to a more bareable rate. I am miserable. Cant do much of anything without causing pain that is hard to get under control. Is there some other reason for my pain that a ct, mri, and blood test wont show? And if it is indeed scarred tissue, is there anything that can be done? The radiation also caused me to be menepausal at the age of 31. I need some kind of hope..i feel like life is just not enjoyable for me or my family. Please Help Me??