Fasting and postprandial mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease.

In order to define the mechanisms of gastroesophageal reflux (GER) in children, we performed simultaneous intraluminal esophageal motility and pH studies in 24 children with symptomatic reflux and abnormal prolonged pH probe study, ten (group A) without endoscopic and histologic esophagitis, 14 (group B) with endoscopic and histologic esophagitis. Median (ranges) age (years) was 5.0 (6 months-10 years) and 3.0 (6 months-12 years), respectively. Recordings were done for 1 hr before and 1 hr after feeding apple juice (15 ml/kg; pH 4.0). All episodes of GER in group A patients and 77.1% in group B patients were accounted for by abrupt transient lower esophageal sphincter (LES) relaxation (TLESR); 22.9% of reflux events in group B patients occurred during gradual drifts of LES pressure (LESP) to undetectable levels. Esophageal refluxate exposure (mean percentage time with esophageal pH < 4.0), the rate of TLESR (number of episodes/hr), and the percentage of TLESRs associated with reflux significantly increased in the fed period both in group A (18.5 +/- 5.4%, 6.2 +/- 2.65, 87.1%) and in group B (29.7 +/- 6.5, 7.8 +/- 3.05, 84.9%) as compared to the fasting state (group A: 10.8 +/- 3.9, 3.9 +/- 3.17, 46.1%; group B: 16.1 +/- 2.6, 4.14 +/- 3.06, 55.17%) (p < 0.01). The rate of LESP drifts (number of episodes/hr) was also significantly higher postprandially (4.85 +/- 1.24 vs 1.8 +/- 0.9, p < 0.01); furthermore there was a postfeeding increase of the LESP drift percentage associated with reflux (79.41% vs 46.15%, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)