Food Safety Report: Walt'z Fish Shak, Boardwalk Place East, Madeira Beach, FL, USA 2 weeks ago • details Suspected food poisoning. Symptoms: Diarrhea, Nausea, Stomach Pain, Cramps, Chills Suspected source: Fish, cold slaw Onset: Less than 4 hours Duration: 4 to 12 hours Additional information: Severe stomach cramping