Food Safety Report: Custard, Culver's, 32nd Avenue South, Grand Forks, ND, USA 2 years ago • details 2 Comments Comment Suspected food poisoning. Symptoms: Diarrhea, Nausea, Vomiting, Stomach Pain Suspected source: Custard Onset: 12 to 24 hours Duration: 4 to 12 hours Sick: 2 people