The primary use of capsule endoscopy is to examine areas of the small intestine that cannot be seen by other types of endoscopy such as colonoscopy or esophagogastroduodenoscopy (EGD). This type of examination is often done to find sources of bleeding or abdominal pain. A colonoscope, inserted through the rectum, can view the colon and the distal portion of the small intestine, the terminal ileum. Unfortunately upper endoscopy or colonoscopy cannot visualize the majority of the middle portion of the gastrointestinal tract, the small intestine. Capsule endoscopy is useful when disease is suspected in the small intestine and can sometimes diagnose sources of occult bleeding or causes of abdominal pain such as Crohn's disease, or peptic ulcers. Capsule endoscopy can be used to diagnose problems in the small intestine, but unlike EGD or colonoscopy, cannot treat pathology that may be discovered.