A 21-year-old woman comes to the university health clinic ...

A 28-year-old woman comes to the office because of a 3-hour history of severe nausea, vomiting, abdominal cramps, and diarrhea. She ate lettuce with salad dressing, custard, and pastries and drank stream water at a family picnic at a local park 2 hours before the onset of the symptoms. She is unsure whether anyone got sick. ................
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