Back pain after fall on bottom down stairs

Patient: I fell while going down the stairs. I bounced down approximately 4 stairs on my butt. The wind was knocked out of me, and due to tensing up I expelled some urine. My tailbone is sore but I can manage, I have notice now however that the area to the left of my spine all down my back is sore. Is this worrisome or will it be fine with rest?