I had a colonoscopy this week and asked Dr. Arya (an excellent physician) not to sedate me. I wanted see what he saw on the large monitor as he explored my large colon looking for and removing polyps (small wart-like growths).
It was truly fascinating! I saw and learned a lot. The colon's tissue is very similar to the inside of your cheek. Blood vessels run very close to the surface and there are many muscular ridges visible. Dr. Arya pointed out the opening to the appendix and another from the small intestine. He took his time to look for polyps and removed six small ones.
If you haven't had a a colonoscopy recently, ask your doctor if you're due for an inspection. And if you're not the nervous type, I highly recommend taking the journey through your "inner passage" while awake.