Definition
GERD is defined as chronic symptoms of heartburn, acid regurgitation, or both, or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus.1 Reflux esophagitis occurs in a subgroup of GERD patients with histopathologically demonstrated characteristic changes in the esophageal mucosa.
Nonerosive reflux disease, also known as endoscopy-negative reflux disease, occurs in patients who have typical GERD symptoms caused by intraesophageal acid but who do not have visible mucosal injury at endoscopy. Functional heartburn is defined as episodic retrosternal burning without evidence of increased esophageal acid exposure or other structural esophageal abnormalities.