What does it mean when you have a shooting pain down the bottom of your butt cheek down in the top of your leg?

Nerve pain. This most commonly relates to compression of the nerve roots as they exit the spinal cord by either spinal stenosis or disc herniation. If severe or associated with numbness or weakness, further evaluation or possibly surgery may be required.
Pain. Usually means the sciatic nerve is getting irritated or pinched by the piriformis muscle in buttock region. Stretching and strengthening help. Sometimes physical therapy and cortisone injection are needed.