Sudden severe abdominal pain and diarrhea, when should i see a doctor?

DONT WAIT TOO LONG: It depends on your definition of severe, i suppose, and what type of pain this is. If it's so severe you can't function get to an er soon. If it's an intermittent cramping pain associated with diarrhea, it may just be a viral process, which should be limited to 12-24 hrs. After that, seek an evaluation. When in doubt, seek help! good luck.