Go to an ENT that specializes in Laryngeal Reflux, and Neurogenic cough, and does the transnasal esophagoscopy right in their office. I have a chronic cough for 30+ years before I was diagnosed correctly. I had been to allergists, gastroenterologists, other ENTs, pulmonologists, had chest xrays etc. . None of them were able to diagnose me correctly, so they never treated me correctly, until up to 2 years ago I found the doctor that knew exactly what was going on with me.