Small bowel capsule endoscopy for the investigation of obscure gastrointestinal bleeding: When we should do it and what should we expect.

Obscure gastrointestinal bleeding is defined as bleeding of unknown origin that persists or recurs (i.e. recurrent or persistent iron deficiency anemia, fecal occult blood test positivity or visible bleeding) after a negative initial workout that necessarily includes gastroscopy and colonoscopy. In clinical practice, small bowel capsule endoscopy is recommended as a third stage examination in these patients, since it is a simple, safe, non-invasive and reliable test. To date there are three available small bowel capsule systems that have gained FDA approval and their diagnostic yield has shown to be superior to other diagnostic modalities for the investigation of the small bowel in patients with obscure gastrointestinal bleeding. The test should be performed as close to the bleeding episode as possible and the administration of a purgative bowel preparation before the administration of capsule endoscopy is recommended by the European Society of Gastrointestinal Endoscopy (ESGE). Issues that still remain to be solved are the definition of bleeding lesions and what really represents a positive finding, as well as the question of whether the outcome of patients with obscure gastrointestinal bleeding is altered after the test, i.e. to better define subgroups of patients that will mostly benefit from capsule endoscopy. In the future small bowel capsule endoscopy might be able to get guided, while tissue samples might be available as well. (Acta gastro-enterol. belg., 2016, 79, 355-362).