Gastroesophageal reflux (GER) usually presents with digestive symptoms, failure to thrive, and/or respiratory symptoms. During the 8-year period from 1981 to 1989, 1,153 children underwent 20-hour pH monitoring to assess GER. All patients were graded using the scoring system of Euler and Byrne. Patients were classified as severe (score greater than 50), moderate (score 25 to 50), and normal (score less than 25). Five hundred (43.3%) of these patients presented with respiratory symptoms including apnea, cyanosis, or "near miss" sudden infant death syndrome (36%), poorly controlled asthma (28%), recurrent bronchopneumonia (13%), bronchiolitis (9%), and miscellaneous symptoms such as intermittent dyspnea, chronic cough, and stridor (12%). Eight patients (2%) had cystic fibrosis. The ages ranged from 1 month to 20 years (mean, 19.5 months). Twelve patients had technically inadequate studies and were excluded. Severe reflux was present in 156 patients (31%) and moderate reflux in 159 patients (31%). All patients were treated initially by medical therapy for a minimum of 8 weeks. The majority of patients (81%) had resolution of their symptoms with change in position, thickened feedings, and, when indicated, additional therapy with metoclopramide, cisapride, or domperidone. Most of these patients were found to have a specific position, usually prone, which decreased reflux. The remaining 57 patients had documentation of persistent reflux by pH monitoring and underwent an antireflux procedure. Of those patients undergoing surgery 51 had severe reflux and 6 had moderate reflux. Forty-four patients had a posterior 270 degrees wrap (Toupet), 10 had a 360 degrees wrap (Nissen), and 3 had an anterior 180 degrees wrap (Boix-Ochoa).(ABSTRACT TRUNCATED AT 250 WORDS)