A colonoscopy is a test where an operator - a doctor or nurse - looks into your colon using a colonoscope. The colon is sometimes called the large intestine or large bowel. The colon is the part of the gut which comes after the small intestine. The last part of the colon leads into the rectum where stools (faeces) are stored before being passed out from the back passage (anus).
This is a companion discussion topic for the original article at https://patient.info/cancer/colon-rectal-bowel-cancer-colorectal/colonoscopy