If you had stomach flu before, what are the things you did to recover faster?

Yesterday morning, my boyfriend took a branded coffee blend drink and vitamins with gluta of the same brand. Last night he wasn’t feeling so well and he started having gas and uneasiness with his stomach. He started feeling sick with light fever, and later that night he puked the stuff he took in the morning. I asked him what color his puke was and he said it was brown/black. I thought that that kind of puke was alarming, since it could be because his stomach is bleeding or it was just because of the coffee.

He told me he felt well after puking, but this morning he started having fever. I told him to take sports drink for electrolytes, and not to eat solid/heavy foods yet. I’m still waiting for other symptoms that might indicate food poisoning (like diarrhea/dehydration) but he’s doing good so far. He’s taking fever medicine, but if he started vomiting again or started having diarrhea, I’m gonna call the doctor.

If you had stomach flu/food poisoning before, what are the things you did to recover faster?