Use of Esophageal String Test to Understand Symptoms, Inflammation, and Function in Eosinophilic Esophagitis

The EST is a gelatin capsule filled with a 90cm nylon string. A trailing end of the string protrudes from one end of the capsule. This end is taped to the cheek and the capsule is swallowed. As the capsule travels to the small intestine, the string inside the capsule is dislodged, leaving a string that goes from the cheek to the small intestine. The capsule dislodges from the string and the string is left in place, in the mouth, esophagus, stomach and small intestine for an hour. During this time, the string rubs against the inside of the esophagus and collects eosinophil proteins. After one hour, the string is removed through the mouth and placed in preservative to save the eosinophil proteins.