This study will look at children with dehydration secondary to gastroenteritis requiring IV rehydration and determine whether the proportion rehydrated after two hours is greater in the children who receive rapid intravenous rehydration (RIVR) or in the children who receive standard IV rehydration.

Despite a movement toward increased use of enteral rehydration, many children still receive prolonged IV rehydration in the emergency department (ED). These children commonly receive a single IV bolus of normal saline followed by the administration of a hypotonic solution at a maintenance rate.

The mean time spent in the ED by children receiving IV rehydration is significantly longer than the mean time required to treat all other conditions. ED overcrowding has been associated with poor outcomes, prolonged pain and suffering, and dissatisfaction. One of the solutions proposed in the American Academy of Pediatrics Policy Statement on ED overcrowding is that hospitals should strive to improve the efficiency of the care provided. One small step in this direction may be to improve our management of gastroenteritis and dehydration.

Inclusion Criteria:

• Acute gastroenteritis as determined by the supervising physician.
• Age greater than 90 days
• Dehydrated and unable to consume sufficient oral fluids to overcome their dehydration state

Exclusion Criteria:

• Weight less than 5 kg or greater than 33 kg
• Underlying disease which may limit the amount of IV fluids given,including but not limited to: hypoalbuminemic states, renal insufficiency, heart disease requiring pharmacotherapy or lesions that may predispose to congestive heart failure, hypertension, chronic lung disease (excluding asthma), diabetes mellitus, severe anemia, and chronic inflammatory disease
• Clinical suspicion by the attending physician of myocarditis or previously undiagnosed cardiac or renal disease.
• History of abdominal surgery or concern regarding an acute surgical abdomen
• Significant head, chest or abdominal trauma within the preceding 7 days
• Bilious or bloody vomitus
• Evidence of hemodynamic compromise (BP < 80 + 2 * age (yrs)) requiring > 20 mL/kg 0.9% normal saline to be administered in the 1st hour
• Bedside glucose < 2.8 mmol/L (see Section 8.3)
• Unable to provide a telephone number or unavailable for follow-up
• Previously enrolled in this trial