Identification of Changes in Gastric Volume and Content by Ultrasound Before and After Chewing Gum

Subjects will fast for a minimum of 8 hours. A baseline ultrasound assesment will be performed to evaluate gastric content. Next, subjects will chew sugarless gum for one hour with changes of gum every 20 minutes (a total of 3 gums will be chewed per subject). Once the last gum is chewed, the gum will be disposed in the trashcan. Three more ultrasound assessments will take place: immediately after one hour of chewing gum, and at the first and second hour after chewing gum has stopped. The content will be classified as empty, with fluids, or with solid. In case of fluids, volume will be measured.