The day before my colonoscopy is commonly my worst of the year. (I have to have one every couple of years.) I have no interest in reading somebody else's experiences.
The colonoscopy itself isn't so bad, because it's under anesthesia -- EXCEPT AT A FEW BRAIN-DEAD HOSPITALS THAT SHOULD BE AVOIDED AT ALL COSTS.
One of those is a famous one -- Columbia Presbyterian in NYC.
It's not just the discomfort of lack of anesthesia -- the tension from the pain can lead to injury to the colon. It happened to me.