Which procedure involves visualizing the entire colon with a scope?

• A. Sigmoidoscopy
• B. Endoscopy
• C. Upper endoscopy
• D. Colonoscopy

Answer: (D)

Visualizing the entire colon with a scope is done with a colonoscopy. A colonoscope is inserted through the rectum and advanced through the entire large intestine, allowing the clinician to inspect the mucosa from the rectum all the way to the cecum and perform biopsies or remove polyps if needed. Sigmoidoscopy, by contrast, examines only the sigmoid colon and part of the descending colon, not the whole colon. Endoscopy is a broader term for internal examinations, with upper endoscopy specifically targeting the esophagus, stomach, and first part of the small intestine. So the procedure that covers the entire colon is colonoscopy.