6. The participant has any complications affecting the esophagus, including Barrett's esophagus (3 cm or more, long segment Barrett's esophagus [LSBE]), eosinophilic esophagitis, esophageal varices, scleroderma, viral or fungal infection, and esophageal stenosis; a history of radiation therapy or cryotherapy for the esophagus; or caustic or physiochemical trauma (eg, esophageal sclerotherapy). However, participants with Barrett's mucosa (less than 3 cm, short segment Barrett's esophagus [SSBE]) or Schatzki's ring (a mucosal tissue ring lining the inferior esophageal sphincter) are permitted to participate.