Do you have a history of stale food or oily and spicy food consumption? If yes, then it could be just Gastritis. If you develop fever, Based on your age, an Ultrasound abdomen is needed. For now, take mild food, plenty of fluids and avoid oily spicy and fried food.
Next Steps
Watch for fever, nausea and vomitings, loss of appetite.
Health Tips
Avoid oily spicy deep fried and non vegetarian food.