My opinion:
Your gallbladder cystic duct is blocked with a large stone, causing the attack. The stone is a new stone, not in the gallbladder long enough to become calcified and so invisible to xray. The material to make the new stone is from the liver cleanses you have been doing, freeing liver stones to move into the gallbladder with bile. As the bile is concentrated, water is removed reducing the ability of the bile to hold suspended cholesterol. The cholesterol precipitates and glues together and grows the new stones from the liver into one capable of blocking the cystic duct.

A direct blood test for gallbladder presence or function doesn't make sense, since it is not a gland and does not secrete anything significant of its presence into the blood.

The hida scan could not find the gallbladder because the radioactive dye could not enter the organ due to its only entrance being blocked by the large non-calcified stone. Strange that they did not consider the more rational conclusion that 'something' had to be blocking the cystic duct, since it is highly unlikely that you have no gallbladder AND no scars (and no memory of GB surgery). They could not consider the possibilty that their test was not totally conclusive, nor are they trained to proceed without this test's 100% efficacy.

Medicine does not recognize the existence of non-calcified gallstones, or any kind of liver stone, even if it is in the gallbladder, so their diagnosis makes sense. The diagnosis of "DUH?" doesn't mean that there is nothing there, it just means "DUH?" and you can take it for what its worth.

Since you're having trouble with attacks since starting the cleansing, your system is eager to dump the stones faster than your current cleansing schedule allows, lucky you! Try cleansing more frequently to avoid the liver stones clumping together into larger stones in the gallbladder and causing attacks. Also increase the concentration of bile salts to prevent gluing together of liver stones within the gallbladder. Fresh raw lemon and beets are good for this. Recipe linked below.

Thank goodness they didn't take your GB, Alan. Their ignorance of the real problem here prevented them from making a sale!

I hope the attack is passed by now and you feel better soon.
Rich

Links:
Beet/Lemon bile tonic to increase bile salts naturally
More Info about Hida Scan

http://www.hmscrown.com/Liver_Cleanse.html
http://www.medicomm.net/Consumer%20Site/tp/tp_c6.htm

Now, I should flush but at the same time I was reading the Liver Flush FAQ and found that the symptoms may get worse if you flush with a blocked cystic dust.

In fact, it seems this is what happened to me after 3 flushes now. The pain increased and got sharper, sounds to me like I have enlarged that blockage some how. If this is the case, is there still any hope of doing the flush? Thank you.

Make sure your colon is cleaned out (colonic) before attmempting a liver cleanse. Stones may not be able to move out easily or may get stuck if the colon is congested. Make also certain to soften the stones long enough (6 days) prior to flushing with apple juice or malic acid (follow all directions to the book). You may also want to use Chanca Piedra extract 20 drops in a glass of water three times per day. If you still have difficulties, taking a table spoon of Epsom salts in warm water relaxs the bile ducts and help clear any stones obstructing the common bile duct. Taking half a cup of beat juice with your next two meals has a similar effect.
Please don't omit the colonic after each liver cleanse, for this could cause major difficulties during your folowing cleanse(s).

Best wishes,
Andreas