My Mom Who Is 80 Went To Dinner On Wednesday

My mom who is 80 went to dinner on Wednesday and came home and in the middle of the night she woke up sick. She has been belching a rotten smell. She doesn't want to eat and drink. And now has no strength. She went to the er yesterday and they sent her home with an antibiotic and now she doesn't want to take that.

Could she have food poisoning, somenilla or ecoli?

What should we do?