Colonoscopies are the subject of jokes because it is scatological.
The procedure itself is nothing to worry about because your mind will be in the clouds due to the anti-anxiety meds you'll be given. In fact, the hospital WILL NOT RELEASE YOU unless you have someone who will accompany you home, by car , bus, or even walking!
Now, the AWFUL part of the colonoscopy is the week before, IF your doctor wants you to go on a liquid (water) diet and follow it with the vile "colon flush" that is often required.
I did this both of the two times I had the procedure, but I've heard some folks who were not asked to do ANY prep at all.