Gastroesophageal reflux (GER) is defined as the involuntary passage of gastric contents from the stomach into the esophagus. GER disease (GERD) on the other hand is a condition that develops if GER causes troublesome symptoms and/or complications such as pain, poor growth, and esophagitis [1]. Regurgitation is defined as the effortless return of stomach contents into the mouth. Vomiting is a coordinated reflex and is defined as expulsion of the refluxed gastric contents from the mouth (Fig. 100.1). However, the difference between regurgitation and vomiting is not always clearcut [1–3].