Colonoscopy is absolutely painless. However, in my case, when I woke up, they took forever to tell me the results (about 30 mins), so expected the worst. I'm an incredible patient person, but in this case I got up of bed and screamed to the nurses: "can you just tell me news now? I can handle it." I later realized they were just having a printer problem, and the doctor had left and they couldn't reach him to speak to me, but everything had come out ok. But I hope people are told the news immediately after they wake up (whether good or bad); some of us have been contemplating impending death since being referred for colonoscopy. They were the longest 30 mins of my life. I've never screamed at somebody, and I wonder whether the anesthesia had anything to do with it.