Is a ct the only or best way to diagnose colon injury after colonoscopy? i had a painful colonoscopy 3 days ago, and while i have no fever, nausea, or other telltale signs of injury, my abdomen still feels sore?

In this scenario you do not seem to have a major problem. However if you still feel uneasy call the person who did the test and get checked

It is not usual to have pain and soreness three days after a colonoscopy, but it is not unheard of. It is not likely that you have a Coleman injury if you are improving. If your symptoms are not improving, however, contact your gastroenterologist. The best way to town would be a physical exam performed by the doctor. Good luck.