Food poisoning? started day before yesterday at night after eating at friends house.real watery stool with no soilds and vomiting.

It's possible, but..: your limited information does not provide enough of a context for symptom onset, severity, or duration. Especially if distress persists, or is accompanied by bleeding, worsening pain, lightheadedness, or development of vomiting or fever, then get a good examination with appropriate testing for reassurance and/or treatment. Wouldn't point fingers unless others got sick from eating the same food.