You can eat before the vaginal examination because the vaginal examination places the probe in the vaginal fornix to observe the pelvic organs and is not restricted by fasting conditions. However, if you choose upper abdominal ultrasound, such as liver, gallbladder, pancreas, spleen or gastrointestinal ultrasound, you need to fast. If you choose lower abdominal gynecological ultrasound, early pregnancy ultrasound, you need to fill the bladder moderately, you can drink, eat, eat must pay attention to try to avoid eating gas-producing foods, such as milk, soymilk, beans, or cold food, because it makes intestinal gas increase, intestinal gas increases, ultrasound is not conducive to the observation of the gas back tissues, sweeping the pelvic cavity structure is prone to leakage, misdiagnosis. Although vaginal ultrasound is not easily affected by interfering factors, but also try to avoid. If you choose to examine small organs, such as thyroid, breast, vascular ultrasound, cardiac ultrasound, you can eat and drink appropriately without restriction.