Poisoning is caused by food bacteria when gastro is seasonal (winter) and of viral origin.
The symptoms of gastroenteritis are almost identical to those of food poisoning, but certain details may help your diagnosis.
If you feel unwell after a shared meal, ask if one of your guests is also sick.
Another major detail, if the symptoms appear within an hour or a few hours after the meal, it is food poisoning.
Gastroenteritis appears after an incubation period of 24 to 72 hours.