Food Safety Report: Sizzler - West Covina, West Covina Parkway, West Covina, CA, USA 1 year ago • details 62 Suspected food poisoning. Symptoms: Diarrhea, Fever, Chills Suspected source: Clam chowder Onset: Less than 4 hours Duration: Several days Additional information: Started with chills and miled fever, also kept burping after eating it.