Its called gastroenteritis (wikipedia?). Gastroenteritis is characterized by periods of stomach pain, fever, dirrarhea, and/or vomitting. Although, it is a usually a viral infection, it can be bacterial. Viral infections cannot be treatment with common antibiotics, so it must run its course. Viruses tend to subside within 2-3 days. My personal experiences lead me to believe you will feel better by tomorrow. Drink ginger ale to help relieve the stomach acid and take an anti-inflammatory drug for the pain. Good luck man.