My grandson who lives with me ate some potato salad that was one day past expiration date and has stomach pain and diearea.. should i take him to doctor.?

Food reactions and minor gut viruses are common in kids. If the kid can take fluids well enough to pee every 6-8 hrs, can walk across the room with minimal discomfort and otherwise looks okay he can be monitored at home. If how he looks scares you take him in. Fever would suggest a virus, no fever-the food. Applesauce, breads and rice are good natural plugs that slow diarrhea.