The inability to belch: a neglected disease in the era of high-resolution esophageal manometry.

Retrograde upper esophageal sphincter dysfunction (R-UESD) is characterized by the inability to belch. Evidence of using high-resolution manometry (HRM) in diagnosing R-UESD has emerged in recent years. We describe the clinical picture and HRM patterns of two patients with R-UESD.