Yes that has come up before, may be you can find the posts in the archives. I would not be surprised if you indeed are clean.
Of course the people that sell supplements would disagree. From the many articles I have read most people have a clean colon if they mostly eat right.
This whole thing started when John Wayne and Elvis Presley died, they probably did not have a very healthy lifestyle.
I don't think it hurts people to clean once a year but in general you might not need it. I have done Oxypowder in the last couple of years, but since then I don't think I have any problems since I changed my lifestyle.
I had a virtual colonoscopy 5 years ago and I saw the picture and did not see anything bad.