I was hoping to use these because I had a hernia during my second pregnancy.  I was a size xs and s in all my other clothing so I assumed the small would work for me.  However, I'm not sure if it was just the pain from the hernia or if it was the panty, but my stomach would hurt so bad by the end of the day.  It seemed as though the panty was a bit tight.  I'm not sure though.  Hopefully the sizing works out better for everyone else who purchases these.