MECHANISMS RESPONSIBLE FOR GASTROESOPHAGEAL REFLUX IN CHILDREN

Background & Aims: There is limited information about the motor mechan isms responsible for gastroesophageal reflux (GER) in children, The ai m of this study was to evaluate the relationship between esophageal bo dy and lower esophageal sphincter (LES) motor events and the occurrenc e of GER, Methods: Concurrent esophageal manometry and pH monitoring w as conducted for 4 hours postprandially in 37 children referred for ev aluation of suspected pathological GER, Presence of esophagitis and/or abnormal esophageal acid exposure was used to classify patients into two groups: those with pathological GER (group A; n = 24) and those in whom GER was not confirmed (group B; n = 13). Results: GER occurred d uring LES relaxations unassociated with swallowing within 5 seconds be fore and 2 seconds after the onset of LES relaxation in 58% (group A) and 69% (group B) of the analyzable episodes. These swallow-independen t sphincter relaxations satisfied criteria for classification as trans ient LES relaxations, An additional 23% (group A) and 19% (group B) of reflux episodes could have been a result of transient LES relaxation associated with swallowing by chance. Persistent absence of LES tone w as an infrequent association of reflux and was confined to group A pat ients (8% of episodes), Conclusions: Transient LES relaxation is the m ost important cause of GER in children. Absent basal LES pressure is a relatively infrequent cause of reflux and only in children with patho logical GER.