Ob-Gyn questions? Ask a gynecologist online.
Thanks for your question.
Most common cause is viral gastro enteritis where a viral infection of the gut causes the diarrhea and / or nausea and vomiting.In most people this is a self limiting infection which improves within few days.
The most important part of care is prevention of dehydration and electrolyte imbalance which may occur due to loss of fluids and salt through diarrhea and vomiting.
You need to get oral re hydration solution from a local pharmacy and give her small amounts of solution at small intervals to keep her well hydrated and to maintain electrolytes.
You may also use pepto bismol as that will help decrease the nausea.It is available OTC at local pharmacy.
If she is still unable to keep the oral rehydration solution and water she may be seen at emergency where they can give her intra venous fluids to keep her hydration.
Please reply for any clarification.