Why does my left buttock pain so much?

Question

i powered walked for a couple hours and the only pain i feel is the left buttock and top of the stomach.

Answer 1

You've sprained a muscle. Or maybe  it's a slipped disc.  Take it easy for a while.

Answer 2

You pulled something. Make sure you are taking deep breaths as you walk to get plenty of oxygen to your muscles. Try to stretch where it hurts.