Is it a stomach bug or something my lil girl might have eat?

[Martha B]

My lil 6 year old had one of those lunch things can't think of it rit at this moment but after eating some of she was saying her stomach started to hurt and started to have the back doors well it stoped and she went to sleep and I want to say about 2 hours later she got up and had to use the bathroom again well she did she went to wash she hands and started to cough and when she cough she gag a lil and got sick but after that she's fine so fare, and I have called around and asked everyone I know there's no bug going around at the moment I even call the er and they told me they haven't seen anything comeing in as of a stomach bug, so I am wanting do this sound like she eat something bad, and she had chilly for lunch at school