help !!! ?

okay so april 13 my son started throwing up after eating and wasn't able to keep anything down so we was to the er and they said a 24 hour bug sent us home it gotten worse and he started diarrhea and throwing up more so we go to a different hospital they do covid test come back negative and they give him medicine to stop him from throwing up he did good with that they sent us home now the same thing is happened and i just want to know what's going on with my son you can tell he is uncontrollable i am trying to wait until i am able to call his doctor but i think i might have to go back to the er has this happened to anyone else???