What Causes Sudden Back Pain?

I have major back pain in my back that occurred sudden. I feel some relief when I drink water, but only for a short period of time. I m able to move around but I can feel the pain when I m walking, standing, sitting, with every day activities. I have taken pain pills (Motrin) which only relieve the pain for awhile then the pain return. My urine had a color of gold, but since I have been drinking plenty of water my urine color is clear with no color. I do not have a fever and have not be nauseated.