Hello, Thanks for your query. First, make sure your doctor have checked for rare tumors and infections in the lower back that can trigger similar symptoms. More often, the problem stems from sprained tailbone ligaments. The physical stress of sitting can eventually cause similar damage if you re overweight. If not, the pain may stem from an otherwise benign bone growth on the end of the tailbone. Mild pain can usually be soothed by taking anti-inflammatory drug such as aspirin or ibuprofen (Advil, Motrin), sitting erect, or sitting on a donut-shaped pillow. But severe pain will probably require stronger treatment. A combination of massage(preceded by a local-anesthetic injection) plus corticosteroid injections usually pacifies the pain. I do hope that you have found something helpful and I will be glad to answer any further query. Take care