Gastroesophageal Reflux in Children and Adolescents

Gastroesophageal reflux (GER) occurs when stomach contents back up into the esophagus (the tube that connects the mouth to the stomach) during or after a meal. A ring of muscle at the bottom of the esophagus opens and closes to allow food to enter the stomach. This ring is called the lower esophageal sphincter (LES). Reflux can occur when the LES opens, allowing stomach contents and acid to come back up into the esophagus.

GER often begins in infancy, but only a small number of infants continue to have GER as older children. Evaluation by a physician is advised for anyone with persistent symptoms of GER.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/gerinchildren/index.htm