Are you put under during a colonoscopy?

"Light sleep": When one undergoes a colonoscopy, often times one is put to a "light sleep" or "twilight sleep", which is a mixture of an anxiolytic (to help you not necessarily remember what is going on) as well as pain medicine to help facilitate the discomfort of the colonoscopy.

Usually: Most physicians in the us sedate their patients before colonoscopy. This means you are awake and extremely relaxed, but many patients due tend to fall asleep with the medications. However, not every physician practices this way and it should be something you discuss with the physician performing the procedure.