Colonoscopy: through the rectum
A flexible camera examines the colon. A clinician can take tissue samples and remove polyps during the examination.
Upper endoscopy: through the mouth
This examines the oesophagus, stomach, and the first part of the small intestine. It does not examine the colon and is not an alternative route for a colonoscopy.
A swallowed capsule is different
A capsule contains a tiny camera. Many capsule studies examine the small bowel; colon capsules are a distinct technology used in selected circumstances. Suitability, preparation, coverage, and availability vary. Capsules cannot remove polyps or take biopsies, so another procedure may still be needed.
Ask what you need to examine
“Which part of my digestive tract are we examining, and what happens if the test finds something?” Your clinician can explain why a particular test fits that question.
This is general education for U.S. readers, not a diagnosis or a personal screening plan. Talk with your clinician about your own history and symptoms. Follow your clinic’s instructions.