My research shows the opposite. Bile acids taken orally actually stop the gallbladder from emptying. It seems the body senses the increase in acids so it stops producing CCK which results in the gallbladder just sitting there since there are already many bile acids in the bowel.
It seems like it can only take a few days for serious problems to happen because of this, I'm thinking this is what happened to me as well.
I've found numerous forums where women go on starvation diets (which also causes gallbladder stasis) and within a week they are in the ER getting their gallbladder removed. So it can happen very quickly.
This is the only idea I have in regards to my situation. However like I said...US didn't see any stones though.
I tried to get my doctor to order an MRCP which gives a more complete view of everything, but they said that treament was not indicated. -_-