One tablespoon of Epsom Salts in a small glass of water will stop a gall bladder attack. If it does not work the same dose can be repeated in about an hour.
Cholestral gall stones do not show on an ultrasound.
I can gaurantee that the quack will want to butcher out your gall bladder. I hope you do not allow this.
Change your diet and keep flushing. We are here for you.