Lying down with a flat stomach and a big stomach is mainly due to the reason of body position, which leads to the change of gastrointestinal contents with the change of body position.
It is a normal physiological phenomenon for patients to have too much abdominal contents due to overfeeding or pregnancy, and when lying down, the contents sink due to gravity, which leads to the abdomen flattening downward, while the abdomen becomes bigger and bulging when standing upright. This is a normal physiological phenomenon. In addition, the above situation may also occur when ascites occurs in patients with cirrhosis of the liver.
The above situation may also be related to other reasons, it is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.