My daughter has had lower back pain, she has had 3 x-rays, none showing spondylolisthesis or spondylolysis but she has heated and iced to help, and she now has discoloration in her lower back, is it bruises or chillblains?

How long is this going on? Was there trauma? injury? recent infection? Fever, chills? N/V/ sore throat? I would have your child checked for strep and infectious disease (EBV) . Check CBC, sed rate CMP. and urine .Also consider MRI or CT to evaluate the pelvis /abdomen / lumbar spine for bleeding/ pathology. Would go to ER today.

My hunch is bruises. Discuss with her.