Gastroenteritis (gastro) typically resolves on its own within a few days with home care, but seek emergency hospital care immediately if you have signs of severe dehydration—extreme thirst, dark urine, dizziness, rapid heartbeat, confusion, or fainting. Go to the hospital or urgent care if you have bloody stools, severe abdominal pain that doesn't improve with rest, signs of severe dehydration, persistent high fever (over 39°C/102°F), or symptoms lasting more than a few days without improvement. You should also seek care if you're in a high-risk group: infants, elderly people, pregnant women, or those with weakened immune systems, as they're more vulnerable to complications. For most healthy adults and children, home management—staying hydrated with water or oral rehydration solutions, resting, and eating bland foods when ready—is sufficient. Watch for warning signs even after initial improvement. If you're ever uncertain whether your symptoms warrant hospital care, contacting your doctor or a nurse hotline can provide guidance based on your specific situation.