Gastroesophageal reflux disease (GERD) is considered one of the most frequent chronic gastrointestinal diseases globally with high costs due to treatment and investigations.First line therapy is with proton pump inhibitors, those who do not respond to initial treatment usually require further investigations such as upper gastrointestinal endoscopy or ambulatory 24-hours esophageal pH monitoring. The total time of exposure to acid and the DeMeester score represent the most useful parameters associated with conventional pH-metry, because they can identify gastroesophageal reflux disease.Although pH-metry is considered the gold standard for the evaluation of gastroesophageal reflux disease, new impedance-based parameters have been introduced in recent years with the role of increasing the accuracy of diagnosing gastroesophageal reflux disease and characterizing the type of reflux. The development of multichannel intraluminal pH-impedance has improved the ability to detect and quantify gastroesophageal reflux. New parameters such as post-reflux swallowing peristaltic wave (PSPW) index and the mean nocturnal basal impedance (MNBI) have recently been introduced to assess GERD phenotypes more accurately. This review evaluates current GERD diagnotic tools while also taking a brief look at newer diagnostic parameters like PSPW and MNBI.

Gastroesophageal reflux disease (GERD) is one of the most common chronic gastrointestinal ailments worldwide, with a high prevalence and extremely costly diagnostic and therapeutic management. A hygienic-dietary regimen, accompanied by weight loss, are important factors for improving the symptoms of reflux disease. Various ways of correct diagnosis and for therapeutic management have been attempted over the years, of which themost widely used diagnostic method is empirical therapy with proton pump inhibitors. Also, questionnaires, upper digestive endoscopy with biopsies, barium radiography, ambulatory monitoring of esophageal pH, pH-impedance and esophageal manometry are widely used. Upper gastrointestinal endoscopy has a good specificity, but a low sensitivity for GERD. Also, the GERQ questionnaire has a good sensitivity and specificity in the accuracy of GERD diagnostic. Barium swallow use belongs to the past, and is recommended mostly for the detection of anatomical anomalies and not for the diagnosis of reflux disease. 24-hour ambulatory monitoring of esophageal pH is the study of choice to confirm the diagnosis of reflux disease in patients without endoscopic modifications suggestive of GERD. The association of impedance to esophageal pH monitoring is the gold standard for diagnosing GERD, making it possible to differentiate between acid reflux, weakly acid and non-acid episodes, and is also useful for diagnosing other conditions that mimic the GERD's clinical symptoms.