Wireless capsule endoscopy is an outpatient approach to studying diseases of the small intestine. Patients with so-called obscure gastrointestinal bleeding are the most common referrals. However, this procedure will likely enlighten the approach to other diseases, such as sprue, Crohn's disease, and carcinoid. Capsule endoscopy enables the physician to examine the entire small intestine for polyps, other benign or malignant growths, and causes of chronic abdominal pain.
During the process, the patient swallows a small capsule, which is about the size of a multivitamin. The capsule exits the stomach very quickly and traverses the small intestine in about 2 - 3 hours. The patient experiences no pain. During this time, the capsule takes pictures of the patient's small intestine at a rate of two pictures per second and transmits the pictures to a velcro beltpack that contains a minicomputer and battery source. The patient goes about their normal daily activities and returns approximately six to eight hours later to the endoscopy department.
There, the beltpack is removed and the computer images are downloaded to a software program that makes the images available for study. Reports are sent to the referring physician and the patient is updated on any findings.
The most common cause of obscured gastrointestinal bleeding is from small blood vessels in the small intestine, termed vascular malformations. These can be photographed and isolated to a region of the small intestine. Some of these lesions are then amenable to endoscopy and cauterization therapy. Others are found more distally in the small intestine and may require surgical attention.
Complications are extremely rare and there have only been a few scattered reports of the capsule being retained within the body and not expelled with the bowel movement the next day. Most of these retensions have been associated with narrowing and deformities of the intestine that would have required small bowel surgery regardless.