The key difference between endoscopy and enteroscopy is the area of the digestive tract they examine. Both use a flexible tube with a camera (endoscope), but endoscopy generally looks at the upper gastrointestinal tract, including the esophagus, stomach, and duodenum. Enteroscopy, however, is focused on the small intestine, a deeper and more challenging part of the digestive system to access. This procedure is often utilized when other tests, such as endoscopy or colonoscopy, have not yielded clear results or when issues in the small intestine are suspected.