Sometimes they cannot see the stones in the ultrasound, or you could have really thick bile.
I would not have the surgery. I have had mine removed. Two of my cousins also. I actually had pancreatitus from a gall stone that got into my pancreatic duct, talk about painful.
Anyway, gall bladder removal should be a last resort. Doctors are way to quick to rip out that organ, that we know is useful. The liver produces bile. The gall bladder stores it and releases just the right amount needed to digest. When your gall bladder is gone, you just have a constant trickle of bile, thus too little when there are foods for it to digest, and too much bile when you have no fats for it to digest. This can cause diarrhea. My aunt has had chronic diarrhea every since she had hers removed many, many years ago. I had diarrhea for months after the removal of mine (with PAINFUL cramping). One cousin has had severe diarhea since his was removed (last year in September) He has lost alot of weight from it. My other cousin has had alot of diarrhea since, but she had diarrhea before it was removed, the gall bladder removal has not fixed whatever her problem is with her stomach.
I have a Liver Flush recipe around her somewhere that softens the stones over a 3 day period, then you stimulate the gall bladder with a drink and this squirts the soften stones out. Then I would do the 5 day intestinal cleanse of Dr. Schulze , then his liver cleanse. Let me know if you want the instructions on the first liver flush. We also have the other products for sale(intestinal #1 and #2, and liver cleanse), we make them ourselves. I have learned so much since I had my gall bladder removed. I wish I knew then, what I know now.