The diagnosis of GERD is best made by the patient’s history.

Objective tests are useful to quantify the severity of disease and to address three questions: Does reflux exist?(2) Is acid reflux responsible for the patient’s symptoms? and(3) Has reflux led to esophageal damage? Reflux may be demonstrated during a barium swallow or by radionuclide scintigraphy after placing technetium-99m sulfur colloid in the patient’s stomach. Esophageal manometry is useful for demonstrating abnormal peristalsis and poor LES tone, but it does not show reflux.

The most sensitive and physiologic test for the presence of acid reflux is prolonged esophageal PH monitoring. This is done by placing a PH probe in the distal esophagus and monitoring acid exposure in an ambulatory state in the patient’s home or work environment. The presence of reflux does not necessarily mean that it is responsible for the patient’s symptoms. Most helpful is the correlation of a patient’s the actual recording of acid reflux episodes during prolonged esophageal pH monitoring. Finally, symptoms resulting from acid reflux do not always correlate with the extent of damage to the esophageal mucosa. This damage is important to identify because patients with esophagitis tend to be more difficult to treat and are more likely to develop severe esophageal complications. Esophageal strictures can be assessed by barium swallow, but to detect subtle may need to ive the patient a solid bolus challenge such as a tablet, marshmallow, or even an aggravating food product. Endoscopy with biopsy is the most sensitive test for reflux-induced mucosal damage.

Endoscopic changes range from extremely shallow linear erosions associated with friability to confluent ulcerations to complete mucosal denudation.

A few patients exhibit Barrett’s epithelium, columnar epithelium in the esophagus that is produced by severe chronic reflux and is associated with an increased risk of adenocarcinoma.