INTRODUCTION: A significant number of GORD patients (30%) continue to perceive symptoms despite PPI therapy. Impedance-pH studies have shown that proximal extent of reflux and presence of gas in the refluxate are the only parameters associated with symptoms perception in refractory GORD. Increased air swallowing (aerophagia) is often suspected based on clinical evaluation. More recently, increased air swallowing between meals was demonstrated, using oesophageal impedance, in a group of patients with increased abdominal gas (x-ray). Aerophagia during meals, however, may be more relevant for GORD patients with postprandial symptoms. We hypothesised that mealtime air swallowing may impact on post-prandial reflux patterns and symptoms in patients with refractory GORD. We aimed to assess aerophagia during meals and postprandial gas reflux in GORD patients, responding or refractory to PPI. METHODS: Mealtime air swallows were quantified using ambulatory impedance-pH monitoring. Normal values were established from 39 healthy controls (mean age 39, range 22–62; Shay et al 2004). We studied 44 consecutive patients (mean age 48, range 19–78) with typical reflux symptoms and pathological oesophageal 24 h acid exposure. 18 were fully responsive and 26 were partially or unresponsive to PPI. Mealtime air swallows were defined as swallows with fast impedance increase (>3000Ω from baseline) in the distal recording segment. Mealtime air swallow frequency (air swallows/10 min meal) was calculated. RESULTS: There was no difference in mealtime air swallow frequency (mean±SEM 8.6±1.0 vs 8.0±0.7 per 10 min) or total mealtime air swallows (67.1±8.3 vs 54.0±5.3) between GORD patients and controls. In the GORD group, PPI-refractory patients had a higher frequency (10.5±1.4 vs 5.9±0.8, p<0.05) and number (83.1±12.7 vs 47.8±7.3, p<0.05) of mealtime air swallows compared to PPI-responders. PPI-refractory patients had a higher number (25.5±4.0 vs 16.8±3.3, p<0.05) and proportion (70.3±3.0% vs 54.0±6.0%, p<0.05) of post-prandial gas-containing reflux episodes than PPI-responders. There was no difference between GORD patients in fasting air swallowing or 24 h acid exposure. CONCLUSION: GORD patients had similar mealtime air swallowing to controls, but both groups had large inter-individual variability. Within GORD patients, PPI non-responders had more mealtime air swallowing than responders. Consequently non-responders had more reflux episodes containing gas, an important factor in reflux perception in GORD patients, who have hypersensitivity to oesophageal distension. Mealtime air swallowing may be amenable to behavioural therapy as an “add on” treatment in patients with incomplete response to PPI and objective aerophagia during meals. COMPETING INTERESTS: None declared.