What Is a Watson Capsule?

A Watson capsule is a device historically used for biopsies in the small intestine. Through the 1960s it, along with similar medical equipment, was used in gastroenterology to collect samples in cases of suspected celiac disease, inflammation, cancer, and other conditions of the bowel. With the development of reliable endoscopy techniques, physicians switched to endoscopic biopsy. There are a number of advantages to endoscopy including better sample quality, more control, and improved patient safety.

To use the Watson capsule, a doctor introduced it through the mouth, along with an attached tube. It was advanced into the small bowel to a site of interest before the surgeon applied suction to the tube, pulling some of the intestinal mucosa into the capsule. This triggered a small knife to cut off a section, enclosing it into the capsule so it could be retrieved and examined by a pathologist.

For safety during the procedure, fluoroscopic guidance was usually provided. This helped the surgeon see in real time where the capsule and tube were so they could be guided to the correct location for a biopsy. In addition, it helped the doctor steer the device carefully to avoid perforations, tears, and other potential complications. With endoscopy, this guidance is not required and patients are not exposed to x-rays during the biopsy procedure.

There were a number of problems with the Watson capsule which made it less suitable as a biopsy instrument, especially with the introduction of different technology. It wasn’t able to penetrate as deeply as some other devices, and couldn’t take deeper samples of the bowel wall. This could result in missed diagnoses if the doctor failed to get a sample from the right location or missed an inflamed spot, something which is harder to do in endoscopic procedures because the surgeon can see the bowel wall.

These devices are not in wide medical use, although studies on the Watson capsule and similar designs for biopsy of the small intestine are still in circulation. Research papers provide insight into how doctors collected biopsy samples before the widespread use of endoscopy, and offer information about the benefits and disadvantages of different capsule technologies. From a medical history perspective, this information can be interesting to have. Physicians may also consider these studies if they are evaluating the potential use of a device like a Watson capsule in a patient or reviewing medical records that include a history of capsule biopsy.