Diagnostic Utility of Amyl Nitrite in Patients With Suspected Achalasia Undergoing High Resolution Esophageal Manometry (HREM)

A single center, prospective study at a tertiary-care referral center (JHH). All patients will be provided with informed consent to undergo HRM with provocation as part of routine care to evaluate dysphagia symptoms or evaluation of known achalasia. All procedures will be performed as part of routine care and therefore no procedures will be performed for the purposes of research specifically. Primary Objective: To determine the diagnostic advantage of the addition of the provocative amyl nitrite test in patients with dysphagia undergoing high resolution esophageal manometry (HRM) Secondary Objective: 1. Measure change of LES pressure after amyl nitrite inhalation in patients with dysphagia undergoing high resolution esophageal manometry (HRM) 2. To assess the ability of amyl nitrite inhalation to differentiate achalasia from pseudoachalasia 3. To assess the ability of amyl nitrite inhalation to differentiate partial fundoplication-related dysphagia versus that due to recrudescence of achalasia in patients who have undergone a prior myotomy. 4. To assess the ability of amyl nitrite inhalation to differentiate post-fundoplication dysphagia from a newly diagnosed motility disorder in patients who have undergone a fundoplication for gastroesophageal reflux disease.