Depends on cause
Most non-specific episodes of acute<unk>  may be discharged, if:
No emergent/urgent cause identified or suspected
Patient tolerating fluids after treatment
No emergent/urgent cause identified or suspected
Patient tolerating fluids after treatment
Nausea and vomiting
ACS/MI
Fever and rash
Boerhaave's
Abdominal pain 
DKA
Abdominal pain
Intracranial Hemorrhage