'Basically the procedure involves inserting a camera up the rectum...'
The colonoscope has a video camera on the end that is connected to a display monitor so the doctor can see and closely examine the inside of the colon. Special instruments can be passed through the colonoscope to remove (biopsy) any suspicious looking areas such as polyps, if needed.
Colonoscopy may be done in a hospital outpatient department, in a clinic, or in a doctor's office.