Proton pump inhibitor non-responsive gastroesophageal reflux disease: unraveling an enigma?

Gastroesophageal reflux disease (GERD) affects 10–20% of adults in Western countries (1,2) and 13% of Americans use medications for GERD at least twice weekly (3). In the USA alone, it is estimated that the annual direct and indirect costs incurred due to GERD is approximately $10 billion (4).