Indications for imaging the small bowel

The small bowel has historically been difficult to evaluate because of its length and tortuosity. Over the last several years, small bowel imaging modalities have improved considerably. There has been an explosion of new technologies aimed at diagnosing and managing diseases of the small bowel. New innovative technology initially brought us the capsule endoscope which revolutionized the approach to evaluating the small bowel. Capsule endoscopy allowed for direct inspection of the small bowel mucosa. This was followed by the development of deep enteroscopy techniques, such as double- and single-balloon enteroscopy, which provide the ability to deliver therapy to lesions deep in the small bowel. In addition to these new endoscopic techniques, cross-sectional imaging with CT and MR enterography has improved considerably and provides complementary imaging. These new modalities have been particularly useful in the evaluation of patients with obscure gastrointestinal bleeding, but are also proving to be extremely useful in patients with inflammatory bowel disease, tumors, polyposis syndromes, celiac disease, and other enteropathies. This chapter reviews these new small bowel imaging modalities as well as the diseases they can evaluate and help manage.