title: Supragastric Belching: Prevalence and Association With Gastroesophageal Reflux Disease and Esophageal Hypomotility.
abstract: OBJECTIVE
  Supragastric belching (SGB) is a phenomenon during which air is sucked into the esophagus and then rapidly expelled through the mouth. Patients often complain of severely impaired quality of life. Our objective was to establish the prevalence of ex-cessive SGB within a high-volume gastrointestinal physiology unit, and evaluate its association with symptoms, esophageal mo-tility and gastresophageal reflux disease.
  
  
  METHODS
  We established normal values for SGB by analyzing 24-hour pH-impedance in 40 healthy asymptomatic volunteers. We searched 2950 consecutive patient reports from our upper GI Physiology Unit (from 2010-2013) for SGB. Symptoms were re-corded by a standardized questionnaire evaluating for reflux, dysphagia, and dyspepsia symptoms. We reviewed the predom-inant symptoms, 24-hour pH-impedance and high-resolution esophageal manometry results.
  
  
  RESULTS
  Excessive SGB was defined as > 13 per 24 hours. We identified 100 patients with excessive SGB. Ninety-five percent of these patients suffered from typical reflux symptoms, 86% reported excessive belching, and 65% reported dysphagia. Forty-one per-cent of patients with excessive SGB had pathological acid reflux. Compared to the patients with normal acid exposure these patients trended towards a higher number of SGB episodes. Forty-four percent of patients had esophageal hypomotility. Patients with hypomotility had a significantly higher frequency of SGB compared to those with normal motility (118.3 ± 106.1 vs 80.6 ± 75.7, P = 0.020).
  
  
  CONCLUSIONS
  Increased belching is rarely a symptom in isolation. Pathological acid exposure and hypomotility are associated with more SGB frequency. Whether SGB is a disordered response to other esophageal symptoms or their cause is unclear.
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: Nikolaos
authors.identifier: http://orcid.org/0000-0002-2482-8465
authors.initials: N
authors.lastname: Koukias
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Woodland
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: Etsuro
authors.identifier: http://orcid.org/0000-0002-5315-4957
authors.initials: E
authors.lastname: Yazaki
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sifrim
keywords: Electric impedance; Eructation; Esophageal motility disorders; Gastroesophageal reflux