Because there are several different procedures that allow your physician to observe the small bowel, your doctor will determine which approach is the best for your individual case. Included here are the different types as described by the ASGE (American Society of Gastrointestinal Endoscopy).
Enteroscopy refers to procedures that use an endoscope to allow a physician to look further into the small bowel (which is up to 25 feet long) than other methods mentioned here. It is primarily used to find the source of intestinal bleeding, but can also be used to find lesions, and determine causes for nutritional malabsorption. The doctor may use a longer conventional endoscope, a double-balloon endoscope, or a wireless capsule endoscope.
An extended version of the conventional endoscope (called a “push endoscope”) may be employed to study the upper part – about 40 inches – of the small intestine. Another similar but longer instrument makes use of the normal digestive contractions of the small intestine to move the instrument further – up to 150 inches – into the small bowel. This procedure takes more time than the “push” method, and still may not be able to see the entire small intestine.
Capsule endoscopy uses a swallowable capsule containing tiny video cameras. The capsule, about the size of a large vitamin pill, contains a light source, batteries, a radio transmitter, and an antenna, and transmits images to a recording device worn around the patient’s waist. When complete, the recording is downloaded to a computer which displays it on a screen. The capsule is disposable and usually takes eight hours to move through the digestive system, after which it is passed harmlessly in a bowel movement. Capsule endoscopy can be used to diagnose hidden GI bleeding, Crohn’s disease, celiac disease, and other malabsorption problems, tumors (benign and malignant), vascular malformations, medication injury, and to a lesser extent, esophageal disease. Currently, capsule endoscopy cannot be used to biopsy or treat any conditions.
Double-balloon enteroscopy uses a basic endoscope for viewing the inside of the entire small bowel, but that endoscope travels inside another tube which is pulled along the inside of the colon by alternately inflating and deflating two small balloons against the inside of the intestinal wall. This allows the scope to travel further, give stable images, perform biopsies, remove polyps, and perform other therapies. This procedure is done under sedation to assure patient comfort. A similar method using a single-balloon device has been recently developed. These procedures can be performed with or without the assistance of an x-ray machine (fluoroscopy).