title: Impact of acid suppression on upper gastrointestinal pH and motility.
abstract: BACKGROUND
  Proton pump inhibitors (PPIs), widely prescribed to patients with upper gastrointestinal symptoms, alter intragastric pH, and may affect upper gastrointestinal transit and motility parameters in addition to affecting the ability to determine Wireless Motility Capsule (WMC) gastric emptying time.
  
  
  OBJECTIVE
  To assess PPI effect on motility parameters of the upper gastrointestinal tract and to determine if PPIs confound ability of WMC to measure gastric emptying time.
  
  
  METHODS
  Twenty healthy subjects were treated with esomeprazole 40 mg bid for 1 week. Another 50 healthy subjects underwent evaluation in absence of PPIs. All subjects underwent WMC test after meal ingestion. After a rapid, sustained luminal pH rise ≥ 0.5 pH units, marking potential gastric emptying time of WMC, an abdominal X-ray (KUB) was taken for gastric emptying time confirmation. Mean pH, pressure and transit time were compared between PPI-treated and untreated groups.
  
  
  RESULTS
  There was no difference in gastric emptying time, small bowel transit time (SBTT), or pressure profiles between the groups. The pH in all cases rose ≥ 0.5 pH units. Distal small bowel pH was significantly lower in subjects on PPIs. Gastric emptying time was identified in all subjects treated with PPIs. Pressure and slope criteria were developed to confirm the time of emptying.
  
  
  CONCLUSIONS
  PPI therapy does not have a significant impact on upper gastrointestinal transit and motility but it does decrease distal small bowel pH. The medication reduced the magnitude of pH change at gastric emptying time but using additional criteria based on slope and contraction frequency, WMC was able to measure gastric emptying time in all patients treated with PPIs.
authors.affiliation: Massachusetts General Hospital, 55 Fruit St GRJ 274, Boston, MA 02114, USA. wmichalek@partners.org
authors.forename: Whitney
authors.initials: W
authors.lastname: Michalek
authors.forename: John R
authors.initials: JR
authors.lastname: Semler
authors.forename: Braden
authors.initials: B
authors.lastname: Kuo
mesh_terms: D000328:Adult; D053704:Capsule Endoscopy; D064098:Esomeprazole / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D054328:Proton Pump Inhibitors / Q000494:pharmacology*; D013686:Telemetry; D041742:Upper Gastrointestinal Tract / Q000187:drug effects* / Q000502:physiology*
chemical_list: D054328:Proton Pump Inhibitors; D064098:Esomeprazole