Green colored urine and back pain- what could this be?

Meds, infection, dye: Your current diet, some medications and urinary infections can result in green urine. Of those, the one that may be most associated with back pain would be a urinary infection. If you are currently being treated for a uti, you may be taking a medication that makes urine blue (+ yellow urine = green). Rarely you could have a type of UTI from pseudomonas. Indomethacin(gout) can cause green urine.

Food dyes, some meds: Can be caused by brightly colored food dyes. Meds such as amytripyline and Propofol can give urine a greenish color. Pseudomonas bacteria causing UTI can also produce greenish discoloration of urine.