Generally speaking, you can drink a small amount of water for ultrasound examination of the liver, because drinking water does not affect the observation of fatty liver under ultrasound. Fasting is required for ultrasound examination of liver and gallbladder, if not, the observation of gallbladder will be affected, because the gallbladder will be contracted after drinking water, which will make it difficult to see the gallbladder under color ultrasound, but drinking water does not have a great influence on the observation of fatty liver, if the patient is only for the purpose of checking the fatty liver, he or she can drink a small amount of water before ultrasound examination, but it is not recommended to drink too much water.