Took my son in today for a cold, fever, and won't eat. Dr saw him and said it was the peak of a…

Took my son in today for a cold, fever, and won't eat. Dr saw him and said it was the peak of a virus and he should be at his worst. A rash was starting to develop when she saw him. She sent us home with nothing. Got home and he started vomiting (multiple times tonight) and has horrible gas. I'm pretty sure they missed something