Capsule endoscopy is a non-invasive diagnostic procedure used to visualize the entire gastrointestinal tract. This method involves the patient swallowing a disposable capsule, roughly the size of a large vitamin pill, which contains a miniature camera, a light source, and a radio transmitter. As the camera travels naturally through the digestive system, it captures images that are wirelessly transmitted to a recording device worn by the patient.
The primary value of this procedure lies in its ability to reach the small intestine, the segment of the digestive tract between the stomach and the large intestine. Standard upper endoscopies and colonoscopies cannot fully examine this region. Capsule endoscopy provides a clear, magnified view of the small bowel lining, allowing clinicians to diagnose conditions that would otherwise remain hidden.
Identifying Obscure Gastrointestinal Bleeding
The primary indication for capsule endoscopy is the investigation of obscure gastrointestinal bleeding (OGIB). This occurs when bleeding persists or recurs after both an upper endoscopy and a colonoscopy fail to locate the source. OGIB can present as overt bleeding (visible blood in stool) or as occult bleeding, often manifesting as chronic iron deficiency anemia.
The small bowel is frequently the source of this undetected bleeding, and capsule endoscopy offers a high diagnostic yield for OGIB, often detecting the cause. The most frequent finding is angioectasia, which are small, fragile clusters of dilated blood vessels near the mucosal surface. These lesions are prone to intermittent bleeding that causes chronic blood loss.
Capsule endoscopy is sensitive for detecting these vascular abnormalities and small ulcers in the small intestine. Localizing the bleeding site guides subsequent therapeutic intervention, such as a targeted endoscopic procedure or surgery. Providing a clear image of the lesion’s location helps direct treatment to stabilize the patient’s hemoglobin levels.
Assessing Inflammatory Bowel Disease
Capsule endoscopy is a tool for diagnosing and monitoring inflammatory bowel disease (IBD), particularly Crohn’s disease (CD) when small bowel involvement is suspected. CD frequently affects the small intestine. CE is often used when initial tests, such as blood work, imaging scans, and ileocolonoscopy, have not provided a definitive diagnosis, but symptoms suggest small bowel inflammation.
The procedure is effective at visualizing early or subtle mucosal lesions characteristic of CD, including superficial ulcers, erosions, and inflammatory changes. Detecting these signs allows for earlier diagnosis and intervention.
For patients already diagnosed with CD, capsule endoscopy helps determine the extent and severity of the disease by assessing mucosal healing and activity. Specialized scoring systems, like the Capsule Endoscopy Crohn’s Disease Activity Index (CECDAI), quantify the inflammatory burden across the small bowel. This detailed map helps clinicians tailor treatment strategies and evaluate a patient’s response to therapy.
Locating Small Bowel Growths
Growths and tumors in the small intestine can be difficult to locate using traditional imaging methods, making them a target for capsule endoscopy. Small bowel tumors, including benign polyps and malignant neoplasms, account for a small percentage of gastrointestinal cancers. These growths often present with non-specific symptoms or bleeding.
Capsule endoscopy provides direct visualization of the small bowel lumen, making it a sensitive tool for detecting these lesions. The procedure can identify tumors and polyps, even those less than two centimeters in size, which may be missed by other techniques. Finding these growths allows for subsequent targeted, invasive procedures, such as deep enteroscopy, to obtain biopsies or remove the lesions.
Diagnosing Mucosal Damage and Other Conditions
Capsule endoscopy is used to assess other conditions characterized by damage to the small bowel lining.
Nonsteroidal Anti-Inflammatory Drug (NSAID) Enteropathy
This condition involves damage, erosions, and ulcerations in the small intestine resulting from chronic NSAID use. CE helps quantify the extent and severity of this mucosal injury, which can cause blood loss and protein malabsorption.
Celiac Disease
CE is utilized when symptoms persist despite adherence to a gluten-free diet. The device can detect villous atrophy (flattening of the small intestine’s lining) and monitor mucosal healing over time.
Inherited Conditions Surveillance
CE is used for surveillance in patients with inherited conditions, such as Peutz-Jeghers syndrome or familial adenomatous polyposis, who are at increased risk for developing small bowel polyps.