That dog died within hours due to acute necrotising pancreatitis. Sadly she never had a chance. The dog passing particularly foul smelling gas. A review of the dog's facial expression is important. That is why a thorough history can be so helpful.
Treatment can be variable due to the scope and severity of the problem.
Often times the animal has indigestion for a day or two and clears up on their own. If the vomiting or diarrhea continues in the happy dog for the third day, I want to see them. If the dog is distressed to any degree, I want to see that pet that day. Based on the physical exam and history, I will determine what tests, if any, are necessary, and then perform the appropriate tests. Occasionally no abnormalities show at that time.