Five-year-old children with stomach pain ultrasound examination of fluid may be related to renal disease, liver disease, intestinal disease and other causes. 1. Kidney disease: such as nephrotic syndrome, there will be a large amount of protein loss from the urine, causing a decrease in plasma colloid osmotic pressure, generalized edema can occur, and even abdominal effusion. 2. Liver diseases: such as viral hepatitis and other liver diseases can lead to hypoproteinemia, which can lead to peritoneal effusion. 3. Intestinal diseases: such as intussusception can cause mesenteric blood vessels to be compressed, resulting in local blood circulation disorders, lymphatic reflux obstruction, abdominal effusion can occur. The five-year-old child’s stomach pain ultrasound examination of fluid may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.