Halo...I had experience same last week.pain went from ribs to back side. I feel like back was on fire somewhere where kidney is located. I went to emergency to hospital. They did my bloods and scan and nothing showed up. Doctor diagnose me with costochondritis which is inflammation of ribs.....it's conditions which is known like not showing on scans or bloods.costochondritis would never show in results. He said is not life treating it could last days, weeks or months. Take painkillers and antiinflammatory. After 3 days of taking lots of tablets pain went away but today it's starting again but only bit so I'm gonna continue with medication to clear it.