1. A diagnosis of functional heartburn should be considered when retrosternal burning pain or discomfort persists despite maximal (double-dose) proton pump inhibitor (PPI) therapy taken appropriately before meals during a 3-month period.
2. A diagnosis of functional heartburn requires upper endoscopy with esophageal biopsies to rule out anatomic and mucosal abnormalities, esophageal high-resolution manometry to rule out major motor disorders, and pH monitoring off PPI therapy (or pH-impedance monitoring on therapy in patients with proven gastroesophageal reflux disease [GERD]), to document physiologic levels of esophageal acid exposure in the distal esophagus with absence of reflux-symptom association (ie, negative symptom index and symptom association probability).