Human: My doctor said I should get a colonoscopy. What is a colonoscopy and why is it important? Assistant: 
A colonoscopy is a procedure in which a doctor uses a thin, flexible tube called an endoscope to examine the inside of your colon. The goal of the test is to detect any polyps or other abnormalities that may be present. These findings can then be further evaluated by a pathologist during a biopsy. Colonoscopies are considered essential for detecting colorectal cancer early when it is most treatable.