You will not be put to sleep to have a Ct scan, you lay on a table with an IV. they then scan you and stop and then add the dye and scan you again. The whole process takes maybe 10 min.
I was having problems and they scanned me and found nothing, I then told them to scope me (Colonoscopy) and it was then that they found my Crohns had come back after surgery.
I'm surprised that you have not had a scope yet.
Good luck, I hope that you don't have Crohns.