What is Gallbladder functioning test?

We go to physicians for help and they are suppose to have our health in mind to make us healthier!  what the heck is this gall bladder funtioning test that they tell us oh your gallbladder is only working 10%.  My next question to him is okay Doc how we going to make it work better.  When he say "We have to take it out".  Now I'm thinking this guy doesn't know what he's doing because if he takes it out the funtion is now down to 0%.  If they call themselves Physcians they surely know how to make the gallbladder start working like it should or do they?  do you really think they can measure funtioning gallbladder by injecting  a solution into and measure the funtion.  where did they get the numbers from to compare what normal funtion is?  I ve seen 12 and 13 yr olds have there gall bladders taken out because of nonfunctioning gall bladder... I'm thinking well I guess it's not funtioning at all now!   In my eyes this make them look like bumbbling  idiots..