title: Delayed gastric emptying and gastroesophageal reflux: a pathophysiologic relationship.
abstract: BACKGROUND
  Delayed gastric emptying (DGE) is frequent in patients with gastroesophageal reflux (GER), but its pathophysiologic role has not yet been established. To identify a relationship between DGE and GER, we assessed whether DGE increases esophageal acid exposure and the related importance of possible mechanisms.
  
  
  METHODS
  Thirty pediatric patients with pathological GER were divided according to gastric emptying scintigraphy into a DGE group (n = 14) and normal-emptying group (n = 16). The esophageal pH-monitoring parameters of the two groups were compared with respect to the individual variation between postprandial and fasting periods.
  
  
  RESULTS
  Patients with DGE had less total acid exposure than did those with normal emptying, but patients in both groups had a pathological fraction of time when pH was below 4 in both the postprandial (median: 18 vs. 27.6; P = 0.49) and fasting (8.5 vs. 23.9; P = 0.01) periods. Patients in the normal-emptying group had similar fraction of time when pH was below 4 in the postprandial and fasting periods. However, patients in the group with DGE had a fraction of time when pH was below 4 in the postprandial period that was almost double that presented in fasting period (postprandial to fasting ratio: 2.11:0.90; P = 0.002). The postprandial to fasting ratio for episodes per hour was similar in the two groups (1.81 vs. 1.79; P = 0.62). Patients with DGE had a significantly higher frequency of long episodes in the postprandial period than did those with normal emptying (62.5% vs. 38.2%; P = 0.04). The occurrence of the longest episode in the postprandial period was also significantly higher for patients with DGE (57.1% vs. 6.2%; P = 0.003).
  
  
  CONCLUSIONS
  DGE seems to accentuate postprandial reflux by increasing the volume of refluxate per episode of reflux through an underlying incompetent lower esophageal sphincter.
authors.affiliation: Division of Pediatric Surgery, Hospital São João, Porto, Portugal. estevaocosta@mail.telepac.pt
authors.forename: J
authors.initials: J
authors.lastname: Estevão-Costa
authors.forename: M
authors.initials: M
authors.lastname: Campos
authors.forename: J A
authors.initials: JA
authors.lastname: Dias
authors.forename: E
authors.initials: E
authors.lastname: Trindade
authors.forename: A M
authors.initials: AM
authors.lastname: Medina
authors.forename: J L
authors.initials: JL
authors.lastname: Carvalho
mesh_terms: D016022:Case-Control Studies; D002675:Child, Preschool; D004943:Esophagogastric Junction / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D019518:Postprandial Period; D011446:Prospective Studies; D013997:Time Factors