Sounds like a kidney stone (still in the kidney) but it could be something else too. Lack of hydration can darken the urine but it should not include blood in it. Dieting often leads to hydration and protein breakdown issues when under physical duress so be sure you are eating and drinking healthily. My guess is that if your eating habits are healthy, then its probably a kidney stone.
Anyway I'm not a doctor so take this with the usual grain of salt. Its only speculation.
Last edited by NealH; 04-01-13 at 12:13 PM.