Underfilling of the gallbladder is a condition in which the gallbladder is underfilled when bile is discharged from the gallbladder during a non-fasting hepatobiliary examination, especially an ultrasound examination of the liver and gallbladder. The function of the gallbladder is to store bile, and after eating, the gallbladder will be stimulated to contract, causing the bile stored in the gallbladder to be discharged, which is manifested as underfilling of the gallbladder. When performing a liver and gallbladder ultrasound examination, it is usually necessary to maintain an empty stomach, the purpose of which is to allow the gallbladder to fill up sufficiently, so as to more clearly observe the gallbladder lumen and the gallbladder wall with or without lesions. Therefore, poor filling of the gallbladder during hepatobiliary ultrasound is not a cause for concern if there is no other discomfort. When performing a liver and gallbladder examination, you should consult your doctor about the preparations for the examination, and if poor filling of the gallbladder occurs, you should take standardized treatment under the doctor’s guidance.