Filled Gallbladder stone

Get them to do it again. Ultrasound is far by the simplest, quickest, and most reliable (and safest!) way to detect gallstones in the gallbladder. Imaging is difficult if you are obese, have a lot of gas in your bowels at the time, or didn't fast properly before the test. Except for being obese none of these should occur in a repeat test. Recommended fasting times vary. I've seen anything from 6-12 hours, but also remember that your gallbladder will need longer to refill after a double-pepperoni pizza than after a bowl of muesli with skimmed milk

CT scans are less reliable at detecting stones in the gallbladder, which is the most common gallbladder problem and what is suspected here, they take much longer and are less safe. They would not normally be used unless something more complex than gallstones is suspected, and usually only in cases where gallstones cannot be found on an ultrasound.

If ultrasound simply proves unreliable because of the amount of fat over the gallbladder or the position of the gallbladder in the abdomen, then an HIDA scan is even more accurate and reliable for detecting gallstones, but it is considerably more invasive and involves a considerable amount of radiation inside the body. It is mostly reserved for more difficult cases or for cases such as detecting gallstones in the bile duct.