BACKGROUND/AIMS: Belching disorder (BD) is clinically distinct from gastroesophageal reflux disease (GERD) with belching. Supragastric belching (SGB) is closely associated with reflux episodes. This study investigates belch characteristics in association with reflux, compared between patients with BD and those who had GERD with belching. METHODS: Impedance pH monitoring data from 10 patients with BD and 10 patients with GERD who exhibited belching were retrospectively analyzed. Belches were considered "isolated" or "reflux-related" and acidic/non-acidic. Belch characteristics were compared between patients with BD and those with GERD. RESULTS: = 0.007). CONCLUSIONS: BD is characterized by more belching, compared to GERD. SGB is more frequently associated with reflux in GERD than in BD; acidity may be related to GERD. In BD, SGB is typically non-acidic and unrelated to reflux. Distinct SGB characteristics may reflect different pathogenic mechanisms of reflux and associated symptoms.