Review Question - QID 214594

An 18-year-old man presents to the emergency department with nausea, vomiting, and diarrhea that started suddenly after eating at a new restaurant. He has vomited 10 times and has had 5 loose bowel movements. His symptoms seemed to have improved 1 hour ago and now he feels fatigued. He is otherwise healthy and takes no medications. His temperature is 98.5°F (36.9°C), blood pressure is 110/71 mmHg, pulse is 117/min, respirations are 11/min, and oxygen saturation is 97% on room air. Physical exam reveals a healthy young man with dry mucous membranes. His gait is stable. The patient states that he no longer feels nauseous. Compared to a visit 1 month ago, the patient has lost 7% of his body weight. During the interview the patient has to leave secondary to another bout of diarrhea. Which of the following is the most appropriate initial management of this patient?