For 88 year old vomiting and diarrhea, what is recommended?

Hydration. If one can not get the vomitting to stop- an 88 year old needs to be seen by a health care practitioner. If this is a simple case of viral gastroenteritis, then medication to stop vomitting and slow diarrhea with plenty of oral hydration can be prescribed. However, if there are more complicating factors- like abdominal pain, fever, past use of antibiotics, then the treatment may be very different.