Capsule endoscopy represents a significant advance in the investigation of small bowel diseases and the beginning of wireless endoscopic imaging. Capsule endoscopy involves swallowing a video capsule endoscope, which is painless and relatively safe. Its use has been established for suspected small bowel bleeding, and the role of capsule endoscopy in the investigation of inflammatory bowel disease, iatrogenic disease, polyposis syndromes and coeliac disease is evolving. It is likely that in many instances it will become the next test after standard endoscopic evaluation. Early data suggest that capsule endoscopy improves outcome in patients with suspected small bowel bleeding, but more data are required on outcomes for the other indications. (Intern Med J 2005; 35: 234-239) Key words : capsule endoscopy, small bowel, obscure gastrointestinal bleeding.The small bowel has remained the final frontier for gastrointestinal endoscopy, due to its remoteness from the mouth and anus, its free intraperitoneal location constrained by loose mesenteric attachments and multiple complex looped configurations. Wireless video capsule endoscopy (CE) is a new technology that for the first time allows complete, non-invasive endoscopic imaging of the small bowel. The Pillcam capsule endoscope (Given Imaging, Yoqneam, Israel) was initially used on a human volunteer in 1999. 1 Subsequently, it was tested in animals and the first clinical trials performed in 2000. 2-4 Since then, over 80 000 studies have been performed worldwide. Previously, small bowel visualization was limited to contrast X-rays, cross-sectional radiology and endoscopically with sonde enteroscopy (never a mainstream technique), push enteroscopy (PE) and intraoperative enteroscopy (IOE). CE was developed because all of these investigations have limitations. Radiological techniques, including small bowel followthrough and double-contrast examination after duodenal intubation (enteroclysis), are relatively insensitive for subtle mucosal lesions, which are the commonest lesions causing small bowel bleeding. 5 PE, using a 2-2.5 m endoscope, does allow therapy to be delivered via a working channel, but can only view the proximal small bowel 15-160 cm beyond the ligament of Treitz. 6 IOE is invasive and is usually followed by a prolonged ileus.
THE SYSTEMThe technology, possible due to advances in miniaturisation, comprises an 11 × 26 mm disposable video capsule propelled by peristalsis. The capsule comprises a transparent optical dome, illumination from six light emitting diodes, a camera, silver oxide batteries, transmitter and antennae (Fig. 1). The field of view is 140 degrees and magnification is × 8, capable of visualizing intestinal villi. The capsule takes two frames per second and the battery life is approximately 8 h, allowing the acquisition of >55 000 images. Images are obtained mainly through intestinal secretions without air insufflation, therefore images are different to conventional endoscopic images. Images are transmitted by radio frequency to a...