I have posted this on the Kidney thread but got no reply ....perhaps somebody reading this could help me...

I have Kidney stones and over the last 2 weeks have had 2 bad episodes of Renal Colic ...today I took a urine sample to my doctors of which they found
Billirubin,Protein,blood and nitrates ...could anyone tell me what this means please ....I have an appointment to see my urologist on Thursday and my GP says I must tell them this .... I've had protein, blood and nitrates before but never billirubin in my urine in fact I'm not sure what it is ....would welcome advice please.