How the Swallowable Balloon Device Helps Detect Barrett Esophagus
1) Swallow: Instead of undergoing standard endoscopy, patients can swallow a pill-sized capsule attached to a thin silicone catheter. The capsule passes through the esophagus and stops near the stomach. 
2) Inflate  & Collect: Once the capsule nears the stomach,  a balloon with a textured surface is inflated  and maneuvered to swab the lower esophagus, where Barrett esophagus (BE) typically begins. A sample of the cells lining the lower esophagus is collected.
3). Swallow: The balloon is deflated through the catheter and inverted back into the capsule, thus protecting the sample from dilution or contamination. After retrieving the capsule through the mouth, DNA is extracted from the balloon's surface for a DNA methylation test.
Device capsule and catheter is smaller than a vitamin pill and a dime.
The small dimensions of the balloon device allow clinicians to retrieve samples quickly and easily without sedation during an outpatient exam.

Source: Moinova HR et al., Sci. Transl. Med., Vol. 10, Issue 424, eaao5848 (2018). Reprinted with permission from AAAS.