A study of pH dynamics in the distal esophagus by 24-hour esophageal pH monitoring in infants and children

Twenty-four-hour esohageal pH monitoring in infants and children has been performed to clarify pH dynamics of the lower esophagus using a pH histogram and acid clearance value in addition to pH score. A pH histogram showing the total state of pH dynamics in the lower esophagus ia constructed with whole pH data obtained by 24-hour pH monitoring. An acid clearance value indication the clearance ability of the esophagus is calculated by pH curves. 1) The normal acid clearance value is under 100. 2) Lower-side-tail of the pH histograms has been analyzed with an acid clearance value and other parameters of gastric acid reflux into the esophagus. Several characteristic pH dynamics are observed in cases of apparently normal patterns and mild gastroesophageal reflux (GER) which were diagnosed by a conventional manner : (a) moderate reflux with good clearance ability, (b) prolonged running status between pH 3 and 4, and (c) mild and pathological reflux with impaired clearance cbility. 3) pH histograms of the GER type are divided into 2 subtypes : The flattened subtype, which indicates ture GER with incompetence of the lower esophageal sphincter (LES), and the peaked subtype, which is often observed in cases of hypertrophic pyloric stenosis and has a well-functioning LES without pathologic GER.