How can you get a diagnosis of bipolar, if you cycle within a day without week long episodes?

You know short but intense moods or episodes, that come and go. I think I’ve got this, my dad has bipolar disorder, by I’ve realised this really fast form of cycling isn’t in the DSM-IV or any other diagnostic book. They say they won’t treat me until I’ve got a diagnosis. http://bit.ly/nl8ckg