A number of studies have shown esomeprazole, an isomer of omeprazole, to produce greater and more sustained gastric acid suppression than omeprazole, due to its greater systemic bioavailability. Several posters presented at Digestive Disease Week [Atlanta, US; May 2001] examined the effect of esomeprazole on gastro-oesophageal reflux disease (GORD) symptoms such as heartburn, particularly in patients with a history of erosive oesophagitis. Esomeprazole was shown to effectively control these symptoms and to provide superior gastric acid control, compared with standard dosages of other proton pump inhibitors (PPIs).