Gastrosophageal reflux is a common symptom during the first year of life. Research indicates that inappropriate relaxation of the lower esophageal sphincter is the predominant factor in causing this problem. Recent studies have suggested that different intracellular messengers may be responsible for antral smooth muscle contraction in the newborn when compared to adult smooth muscle. The possibility that these contractions may lead to reverse peristalsis with inappropriate relaxation of the lower esophageal sphincter deserves further investigation.