A 9 year old boy presents to the clinic with vomiting for 6 hours.  He has vomited 3 times and a moderate amount in volume. The emesis is clear and not forceful. He does not have any reported abdominal pain. He has voided 2 times today and has had one normal bowel movement. Earlier this morning he was playing baseball and was struck by another player. There was no reported loss of consciousness. He sustained no obvious injuries. Physical Examination: He looks well.  Abdomen is not distended. On auscultation, bowel sounds are normal. On palpation it is non-tender and there are no masses or organomegaly. The remainder of the physical examination is normal.