In general, in the absence of active infection, gall bladder pain is from a stone passing thru the bile duct. This may be part of why the pain you've experienced is intermittent.....the stone is very small and passes into the digestive tract and nothing more is heard from it till the next time.  When things get real is when the stone fails to pass and is trapped in the duct....it's usually got a whole bunch of it's little buddies behind it inside the gall bladder, so removal of the organ is indicated. When we consume fats, the gall bladder is supposed to release bile into the digestive system to digest it......so the stones tend to move as a result of that trigger of fat calling for the release of bile.