My father is 65, for the second time in a few months he has been suddenly throwing up, being very pale and shaking uncontrolably, and saying that he  has a tender stomach. The last time after maybe 4 hours he was feeling somewhat better but continued to feel drained for days. We have no idea what is wrong.
He is either suffering from an infection, a metabolic disorder of his electrolytes, liver, or kidney enzymes, or deny Chat Doctor.  You should strongly advise him to seek out a doctor right away by way of his own primary care specialist or take him to an Urgent Care or ER.  Sounds like he needs lab work and perhaps some IV fluids to pump him up a bit. Please rate this a 5-STAR ENCOUNTER and write me at: www.yyy.ly/yyyyyyyyyyy with more questions.