The National Institute for Health and Clinical Excellence (NICE) has issued full guidance to the NHS in England, Wales, Scotland and Northern Ireland on wireless capsule endoscopy for investigation of the small bowel.
Obscure gastrointestinal bleeding is defined as bleeding of unknown origin that persists or recurs after a negative initial endoscopy (colonoscopy and/or upper gastrointestinal endoscopy). Diagnosis may be difficult because bleeding can often be slow and/or intermittent. Patients may experience prolonged blood loss, leading to iron deficiency (anaemia) and a feeling of tiredness.
Small intestinal bleeding can result from a number of conditions, including vascular lesions (angiodysplasia), small bowel tumours, coeliac disease and Crohn’s disease (which may be suspected because of other symptoms).
The patient swallows a small capsule, usually after an overnight fast. This capsule consists of a camera, a light source and a wireless circuit for the acquisition and transmission of signals. As the capsule moves through the gastrointestinal tract, images are transmitted to a data recorder, worn on a belt outside the body. These data are transferred to a computer for interpretation. The capsule is then passed in the patient’s stool and not used again.