Esophageal Motility in Reflux Induced Cough

Inclusion criteria: 1. Adult patients (ages 18-75 years old) 2. Cough for more than 8 weeks 3. Additional clinical evaluation of cough including a complete pulmonary function test with methacholine challenge and a high resolution CT scan of the chest. 4. Ability to understand the purpose and nature of the study 5. Willingness to participate and provide consent form Exclusion criteria: 1. Actively smoke in the preceding 6 months. 2. Recent respiratory tract infection (\<4 weeks). 3. Drink above the recommended safe alcohol limit (21 units per week). 4. History of respiratory or gastrointestinal malignancies. 5. Previous gastrointestinal surgery (excluding minor surgeries, such as cholecystectomy, appendectomy). 6. Subjects with established and significant cardiac, pulmonary, or neurological disorders as deemed by the clinician or study personnel 7. Use of angiotensin converting enzyme inhibitors 8. Use of H2 blockers or proton pump inhibitors in the seven days prior to reflux testing (impedance/pH), or inability to withhold such medications for the duration of the study 9. Women of childbearing potential, using adequate birth control. Adequate birth control includes: (i) hormonal methods, such as birth control pills, patches, injections, vaginal ring, or implants; (ii) barrier methods (such as, a condom or diaphragm) used with a spermicide (a foam, cream, or gel that kills sperm); (iii) intrauterine device (IUD); or (iv) abstinence (no sex). Adequate birth control must be maintained for the duration of the study. Women not using adequate birth control will be excluded from the study, as funding for the pregnancy tests was not included in the small grant awarded for this study. 10. Nursing mothers will be excluded. 11. Persons with allergies to citrus will be excluded. 12. Inability to understand the purpose and nature of the study 13. Unwillingness to participate and provide consent form