Hida Scan with CCK

I am having a Hida Scan w/CCK 2 days from now at noon.  My instructions are to eat a fatty meal 6 hours prior to Noon.  Why am I instructed to do this?  My symptoms are nausea and vomiting.  What are the Doctors looking for in the Gall Bladder?

[boron]

Usual instructions for preparation to HIDA is - not eating some hours before the test. Fatty meal is sometimes given during the test itself. Having a fatty meal 6 hours prior to test sounds a bit unusual for me, so if you can call and speak with some nurse about it...

HIDA scan shows function of your gallbladder - is it contracting and ejecting the bile properly or not. Gallbladder and bile ducts, even when no gallstones are found in them, may contract improperly and cause upper right abdominal pain, nausea and vomiting.