As in most instances of illness, everybody responds differently. Some individuals will have very mild symptoms, while others may go on to have more significant complications associated with Escherichia coli or other foodborne illness. If your symptoms are mild and have been time-limited, just keeping up with the fluid demand by drinking plenty of water or sport drinks containing electrolytes should be adequate to keep hydrated. Vomiting greater than 24 hours is a key indicator that you should seek medical treatment. If diarrhea becomes bloody, this too would be a reason to seek medical advice.
With more severe cases of food poisoning, it is best to seek medical treatment at a certified urgent care that is capable of providing you with IV fluids and medication to stop the vomiting cycle.