I had a urinalysis done for some trouble I was having with some burning urination and very concentrated urine that would sink to the bottom of the toilet. The test came back negative for infection and the doctor told me that my urine was just very concentrated and that I was probably dehydrated. I ve been keeping hydrated but my urine is still very concentrated at the bottom of the bowl even when light in color. I also experience occasional side and back pain. I ve had these symptoms since December 2013. Should I go in to the doctor again? What could this be?