title: New developments in detection of gastroesophageal reflux.
abstract: OBJECTIVE
  Esophageal pH monitoring has been considered the gold standard for the diagnosis of gastroesophageal reflux disease. In many patients, however, there is a poor correlation between acid reflux episodes and symptoms. The high prevalence of nonerosive gastroesophageal reflux disease and functional heartburn associated with normal esophageal ph-metry and the nonnegligible proportion of patients with gastroesophageal reflux disease refractory to adequate proton pump inhibitor therapy are now recognised. Efforts have been made to detect all types of gastroesophageal reflux and to increase the likelihood of documenting the relation between symptoms and reflux events by prolonging the recording periods. This review summarises the recent developments in detection of gastroesophageal reflux.
  
  
  RESULTS
  The focus for acid monitoring has been expanded from the conventional site at 5 cm above the lower esophageal sphincter to the entire esophageal body: from the squamocolumnar junction to the upper esophageal sphincter. A wireless pH monitoring system has been validated as an alternative to catheter pH monitoring and shows better tolerability. Finally, esophageal impedance monitoring, combined with ph-metry, allows detection not only of acid reflux but also of weakly acidic and alkaline reflux and promises to become an important clinical tool, particularly to assess gastroesophageal reflux in the postprandial period and in patients on proton pump inhibitor therapy with persistent symptoms.
  
  
  CONCLUSIONS
  Key developments in the recognition and diagnosis of all types of gastroesophageal reflux will have significant implication for understanding the pathophysiology of reflux disease and will influence clinical practice in gastroesophageal reflux disease.
authors.affiliation: Centre for Gastroenterological Research, Catholic University of Leuven, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Emerenziani
authors.forename: Daniel
authors.initials: D
authors.lastname: Sifrim
mesh_terms: D017097:Electric Impedance; D004947:Esophagus / Q000378:metabolism* / Q000503:physiopathology; D005744:Gastric Acid / Q000378:metabolism*; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008991:Monitoring, Physiologic / Q000379:methods / Q000639:trends; D013686:Telemetry / Q000379:methods