Colon is also known as the large bowel.

Colonoscopy uses a thin, flexible tube like scope that has a miniature video-imaging equipment and lighting at its tip. The scope is passed through the anus into the colon allowing the physician to examine the colon in detail. The goal is to completely examine the colon all the way to the end of the small intestine, called the ileum.  This allows for the complete examination of the colon from anus to ileum.

Prior to the start of the procedure patients are given IV medications to relax them during the procedure. It is for this reason that patients are required to have someone drive them back home after the procedure.

Depending on patient's age, family history and other factors sometimes growths called polyps and other abnormal tissues are found in the colon during the exam.  When such growths are found or suspected, the doctor will remove small samples called biopsies that are sent to the pathology lab for further analysis.  Your doctor has several techniques for removing the polyps using the same scope used for the colonoscopy.