Don't purposely give your self that kind of illness. If you had loose stool for a while and it has stopped, chances are that your natural flora is back to normal.
By purposely giving yourself food poisoning, you stand the risk of appendicitis, gastroenteritis as well as a dozen of other diseases which can potentially kill you or result in a costly surgery.
I for one had Gastro and it f-ing sucks.
The simple thing to do is give them a sample of what you have. That way they can get appropriate bacteria counts and if you did have a problem (Such as E-coli or Salmonella) They can see if you've recently recovered.