Here are some suggestions:
You should drink something every time you have an episode of vomiting or diarrhea. Take small slow sips of a cup Pedialyte or Gatorade. You might also try drinking clear soda, such as 7UP or Sprite; clear broths; or non-caffeinated sports drinks, such as Gatorade. Affected adults should try to drink plenty of liquid every day, taking small, frequent sips.
Ease back into eating. Gradually begin to eat bland, easy-to-digest foods such as soda crackers, toast, gelatin, bananas, rice and chicken. Stop eating if your nausea returns.
Try the BRATTY diet: Small amounts of Bananas, Rice, Apples / apple sauce, Tea, Toast, or Yogurt
Avoid certain foods and substances until you feel better. These include dairy products, caffeine, alcohol, nicotine, and fatty or highly seasoned foods.
Adapted from the Mayo Clinic.