A 8 year old girl is brought to the emergency room by EMS after having diarrhea and a history of fever for 5 days. She is otherwise well. Immunizations are up to date.  Family history reveals that all family members are well. Social history is negative. Upon examination, the patient appears dehydrated. The patient is responsive but lethargic. The neurological,respiratory, and skin exams appears normal. The cardiovascular examination shows normal heart sounds. Mucous membranes are dry, pulses are palpable but weak, capillary refill is 5 seconds centrally and peripherally. The abdominal examination reveals vague and diffuse pain.