How does stomach sonogram work? Can you explain what happens?

Abdominal sonography. Simple test with gel and transducer allows the technologist to see inside your body using sound waves. It shows up on a screen. Interpretation of the images is key here. They use this to look at your liver, aorta, kidneys, spleen, pancreas and gallbladder and biliary tree.
Ultrasound. A sonogram is a synonym for ultrasound. It's the same physical principle as the doppler effect and similar to how radar works. A high-frequency soundwave is generated and directed at the target (stomach). Its path is affected by fluids & matter. The echo back is received by the machine and a picture is generated based on the echo times. The technician or doctor can then compare this to normal.