Review Article

The Diagnosis and Investigation of Obscure Gastrointestinal Bleeding

K. Liu; A. J. Kaffes


Aliment Pharmacol Ther. 2011;34(14):416-423. 

In This Article

Abstract and Introduction


Obscure gastrointestinal bleeding (OGIB) is a commonly encountered clinical problem in gastroenterology and is associated with significant morbidity and mortality. The investigation and management of OGIB has changed dramatically over the past decade with the advent of newer gastroenterological and radiological technologies.
To review the current evidence on the diagnosis and investigation of OGIB.
We searched the PubMed database (1985–2010) for full original articles in English-language journals relevant to the investigation of OGIB. The search terms we used were 'gastrointestinal bleeding' or 'gastrointestinal hemorrhage' or 'small bowel bleeding' each in combination with 'obscure', or 'capsule endoscopy', or 'enteroscopy' or 'enterography' or 'enteroclysis'.
Capsule endoscopy (CE) or double balloon enteroscopy (DBE) should be first line investigations. They are complimentary procedures with comparable high diagnostic yields. DBE is also able to provide therapeutic intervention. Newer technologies such as single balloon and spiral enteroscopy are currently being evaluated. Radiological and nuclear medicine investigations, such as CT enterography and CT enteroclysis, are alternative diagnostic tools when CE or DBE are contraindicated. Repeating the gastroscopy and/or colonoscopy may be considered in selective situations. An algorithm for investigation of obscure bleeding is proposed.
The development of capsule endoscopy and double balloon enteroscopy has transformed the approach to the evaluation and management of obscure gastrointestinal bleeding over the past decade. Older diagnostic modalities still play a complementary, but increasingly selective role.


Obscure gastrointestinal bleeding (OGIB) is defined as persistent or recurrent bleeding from the gastrointestinal (GI) tract after negative evaluations with upper and lower endoscopies. This represents approximately 5% of all GI bleeds.[1–3] Obscure GI bleeding can be further categorised into obscure overt GI bleeding in patients with clinically evident bleeding (haematemesis, melaena and haematochezia) or obscure occult GI bleeding which manifests as iron deficiency anaemia or positive faecal occult blood test (FOBT). Common causes of OGIB are listed in Table 1.

Although missed lesions from oesophagogastroduodenoscopy and colonoscopy occur frequently, evaluation of OGIB usually focuses on visualisation of the small bowel. As a result of technological advances in endoscopy, there has been a paradigm shift in the evaluation of OGIB and small bowel bleeding over the past decade. Modalities used to investigate the small bowel previously such as push, Sonde and intraoperative enteroscopy are now limited to increasingly selective situations. Newer technologies including capsule endoscopy (CE) and double balloon enteroscopy (DBE) both play a major role in the evaluation of OGIB today.

In this article, we review the clinical evaluation of obscure gastrointestinal bleeding.


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