I had one in January, and the throat one immediately before it. The throat one was awful. I gagged when they inserted the camera tube, and it was very uncomfortable for the minute or so of the procedure.
The colonoscopy was not as uncomfortable. It took about ten minutes to complete. They were looking for reasons my iron levels have dropped, but found nothing untoward.
The prep for the colonoscopy is very unpleasant. I had to drink 500ml of an awful tasting liquid, which was salty with a vague hint of orange, followed by 1 litre of water. Then wait for the after effects. Repeat this two hours later, and then spend the rest of the night within close proximity of the toilet.
Overall, a pretty horrible experience. (The prep).
