This is a somewhat difficult question to answer, because experiences vary. In general it shouldn't be a bad experience. It can be somewhat uncomfortable, but your doctor
should give you two medications through an IV. One of them is usually a fast acting pain medication such as Fentanyl. The other is a medication that causes you to relax and feel sedated. One such medication commonly used is Versed. The fentanyl should take care of most of the pain. Versed will make you sleepy. The effects of Versed (based on how sensitive your body is to it and how much you receive) are to make you sleepy and help you take your mind off of the procedure. Many times, patients go into a brief, light nap and don't even remember the procedure, which would be optimal. These medications are given in moderation because your breathing and vitals such as your heart rate and blood pressure must be maintained at safe levels.
It must be stressed that a colonoscopy
is a very important procedure and the slight discomfort you may experience should not deter you from getting it done. It is a screening as well as a therapeutic tool that is relatively low risk and easy to perform. But the benefits can be great. As always, you should talk to your doctor if you have questions or concerns regarding the procedure.