Pathophysiology of gastroesophageal reflux and distal esophageal motility in children with gastroesophageal reflux disease.

We investigated the mechanisms of gastroesophageal reflux (GER) and esophageal motility during endogenous esophageal acid exposure in 17 patients with reflux disease alone (age range 3-20 months) (group A) and in 10 patients with reflux disease complicated by esophagitis (age range 4-19 months) (group B), by simultaneous recording distal esophageal sphincter relaxation was the predominant mechanism of reflux in both groups of subjects; however, it was more frequent in group B patients (Bpts), whereas reflux episodes due to appropriate sphincter relaxation were detected more frequently in group A patients (Apts). During endogenous acid exposure, primary peristalsis was the most frequent esophageal motor event in all patients; furthermore, its amplitude was significantly higher in Apts as compared with Bpts. Primary peristalsis was more efficacious (rise of intraluminal pH by at least 0.5 unit) in patients with reflux disease alone, whereas nonspecific motor irregularities were more common in children with reflux esophagitis. It is concluded that the major mechanism of GER in patients with reflux esophagitis is an inappropriate sphincter relaxation; reflux due to appropriate sphincter relaxation is associated with less severe reflux disease; and patients with esophagitis exhibit a deranged esophageal motility during spontaneous acid exposure.