Ultrasound of the liver, gallbladder and spleen requires fasting, especially after meals, which has a greater impact on the gallbladder. Because the bile in the gallbladder will be emptied after eating, so that the gallbladder contraction can not see the gallbladder wall and the structures in the gallbladder cavity, which will cause a missed diagnosis. For the liver, the increase in gas after a meal will cause an increase in gas, and the increased gas will cause significant attenuation of the ultrasound, resulting in poor display of certain sections of the image and affecting the diagnosis. It is recommended that for general liver, gallbladder and spleen ultrasound, it is necessary to fast for more than 8 hours, and it is also better to request the ultrasound of liver, gallbladder and spleen in the morning as much as possible, because the gas production in the abdomen will naturally increase in the afternoon, which will affect the observation effect of ultrasound.