Abdominal pain, rectal bleeding

I have been expericencing severe abdominal pain along with large amounts of blood and mucous in my stool. I have internal hemmerhoids and polyps. I have also had a few doctors diagnose me with Chrons disease, and then a couple have told me afterwards that I don't have Chron's. I also have been diagnosed with Colitis and IBS. I have had numerous colonoscopies, endoscopies, CAT scans, X-rays and MRI's to try to determine the cause of the pain. Every doctor has basically thrown thier hands up and said they don't know whats wrong with me and send me home with meds they think should help. I have been in and out of the hospital for the last few months with no success. The abdominal pain has gotten unbearable and the pain pills do nothing to alleviate the pain. Also, the blood is literally just pouring out of my rectum, for about 4 days now. This has been happening on and off for a few weeks. But, no one can figure out what is wrong with me? Any suggestions would be great. BTW I am a 35 year old male and my mother passed at 52 from colon cancer. thanks!