The most recent clinical guidelines published by the American College of Gastroenterology supports empiric treatment with proton pump inhibitor (PPI) medication for patients with suggestive clinical symptoms of GERD [9], and without any alarm symptoms. In this setting, resolution of symptoms following PPI use may be diagnostic. Alarm symptoms, such as dysphagia, odynophagia, weight loss, or bleeding, should trigger additional evaluation for GERD-associated complications, as well as any patients with persistent symptoms on empiric therapy.

Upper endoscopy, or EGD, is the mainstay of GERD-associated symptom evaluation. In patients with clinical alarm symptoms, older age, confounding illnesses or multiple competing diagnoses, or poor response to empiric therapy, further evaluation with EGD is indicated [9]. Detection of erosive esophagitis, peptic stricture, Barrett’s esophagus, or malignancy can support a diagnosis of GERD and offer targets for direct intervention. Additionally, competing diagnoses such as peptic ulcer disease and non-reflux esophagitis, including infectious and eosinophilic, can be excluded.

Barium swallow has largely been supplanted by EGD for anatomic evaluation of symptoms associated with GERD complications. However, a finding of hiatal hernia, sometimes missed on EGD, and possibly frank reflux of contrast, would present an anatomic risk for GERD separate from TLESR, with implications for peri-operative planning. In rare cases, barium swallow may diagnose an esophageal diverticulum, which may also result in GERD-associated symptoms. A full-column barium swallow may also sufficiently distend the esophagus to reveal an otherwise occult muscular ring, which can be missed on EGD given the difficulty of retaining air for sufficient distention during careful inspection of the lower esophagus. Given these findings, barium swallow has been advocated by some radiology experts for further evaluation of GERD symptoms with concomitant dysphagia. Other types of esophageal imaging include video fluoroscopy/ modified barium swallow (MBS), which is more commonly used to assess aspiration, as well as oropharyngeal dysphagia and suspected extraesophageal manifestations of GERD. MBS may be diagnostic and therapeutic, in helping to identify maneuvers and food consistencies that reduce aspiration risk. Air contrast or double contrast barium swallow allows for the non-invasive assessment of esophageal mucosa, but has largely been replaced by EGD for direct visualization. Similarly, timed barium swallow can be used to assess esophageal transit, but has been supplanted by esophageal manometry testing, discussed in detail below.

Ambulatory pH testing offers direct assessment of reflux episodes and symptom occurrence in patients with GERD-associated symptoms requiring further evaluation. General indications include clarification of GERD diagnosis in patients with persistent symptoms and without mucosal damage on EGD; assessment of treatment adequacy in patients with persistent symptoms on PPI; and pre- and post-antireflux surgery evaluation [9]. To assess for contribution from baseline GERD, testing is performed after holding PPI treatment for at least 7 days. The options for direct pH testing include multichannel intraluminal impedance and pH (MII-pH), BRAVO^® pH capsule (Given Imaging, Yoqneam, Israel), and ResTech™ (Respiratory Technology Corporation, San Diego, CA, USA) . MII-pH is a trans-nasal catheter that monitors acid and non-acid reflux over a 24-h period, and includes sensors in the proximal and distal esophagus. BRAVO^® is a directly deployed capsule that monitors acid reflux over 48–96 h. In both cases, patients receive a wireless transceiver unit to document body position, meal periods (which are excluded from analysis), and symptom events. ResTech™ is a single-channel pH probe device which can be placed without need for manometry or endoscopy. It detects both liquid and aerosol reflux in the oropharynx, and is particularly useful in the assessment of patients with extraesophageal symptoms and suspected laryngopharyngeal reflux (LPR) [10]. The pros and cons of each technique are outlined in Table 2.2. However, in most cases, pH or combination impedance-pH testing have sensitivity and specificity of 65–75%, which is much lower compared to endoscopic evidence of esophagitis in making the diagnosis of GERD.