What Causes Lower Back Pain Along With Red Coloured Urine?

I have lower back pain on my left side. I do drink quite moderately.. i have noticed this pain more so when i lay down. my urine is also a reddish color. Although it does not hurt in my abdominal area it is almost a dull frequent pain I can hit my back in the area of concern and it does not affect the pain level. I am concerned i may need to go to the doctor.