Food Safety Report: McDonald's, West San Marcos Boulevard, San Marcos, CA, USA 1 year ago • details 61 Comments Comment Suspected food poisoning. Symptoms: Diarrhea, Nausea, Cramps, Chills, Headache Suspected source: McDonalds Big Mac/ Nuggets Onset: 1 to 2 days Duration: 12 to 24 hours Sick: Me