rainbow,
When I had gall bladder attack and went to ER, the ultrasound technician had me cough, then she pounded on my back right as I coughed....she said she was trying to move the stone out the "neck of my gall bladder". I asked if she got it to move and she said yes. I do not know if she really did get it to move, the attack had already stopped by then, or I could not feel the pain any more due to Vicodin.
You made me remember this...when I read your post about you feeling better when some one pounds your back.