6. Has a history of or any coexisting diseases affecting the esophagus (eg, Barrett's esophagus, eosinophilic esophagitis, esophageal varices, scleroderma, viral or fungal infection, or esophageal stricture), history of radiation therapy or cryotherapy to the esophagus, caustic trauma, or physiochemical trauma such as sclerotherapy to the esophagus.