The exclusion criteria will be: i) a history of thoracic, esophageal or gastric surgery, ii) primary or secondary esophageal motility disorders, iii) use of non-steroidal anti-inflammatory drugs and aspirin, iv) presence of Barrett's esophagus, erosive esophagitis, peptic stricture and duodenal or gastric ulcer on upper endoscopy, v) eosinophilic esophagitis, vi) underlying psychiatric illness, vii) pregnancy in women, viii) refusal to participate.