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

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.

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.