Many years ago in Germany (still they do it and in other places they do it), you can check by oral cholecystogram. After the oral cholecystogram is done, the dye gets in the gallbladder, and you can do two things: 1.) Give the patient high protein, high calorie American breakfast diet, or 2.) you can give IV cholecystokinen. You see that the gallbladder is functioning, that it contracts. We did so many years.
Now, a little bit more civilized, but more expensive way, can be done, which we will do in our protocol: HIDA-scan. When you give the HIDA-scan, radio opaque material goes to the gallstone, gallbladder. Feel the gallbladder, and after the gallbladder takes the HIDA, give the IV cholecystokinen and check gallbladder contraction, you can say 50%, 60% ¾ you need to see at least 50% contraction. At this time in the market we don't have pure cholecystokinen. It's very expensive. I don't think it's necessary, but Kinevac is available (5 micrograms). We use IV with very little side-effects.