yes , i had a kidney stone moving around, ann i had to go to my pain dr. for my monthly visit! well each month i have to take a drug test to get my medicine, and when i peed in the cup it was very redish, can the protines in the blood cause a test to show positive for like marjuana, since i dont do street drugs , or smoke that stuff, i dont under stand why the test showed up positive for this, ?????