Try to get 1 or 2 liverflushes in before your US. At least you will feel better, but if you have calcified stones they still will show up, but because of the cleaning they will just be quiet and happy.
If you are afraid of stuck stones, use one of the flushes that uses epsom salt. I think it is mainly doctors that try to scare you about stuck stones.
Drink applejuice (liter) every day to soften the stones.
And also drink half your body weight in ounces of water (disstilled) every day.
THere is so much to say, so I suggest to read as much as you can on this forum.