Small intestinal interstitial fluid may be due to abdominal inflammation or abdominal tumor, or it may be due to hypoproteinemia and so on. 1. Inflammation of the abdominal cavity: If inflammation of the abdominal cavity occurs, such as appendicitis, pancreatitis, pelvic inflammatory disease, etc., due to the stimulating effect of inflammation, there will be seepage in the abdominal cavity, which may lead to intestinal interstitial fluid accumulation. 2. Tumor in the abdominal cavity: if there is a tumor in the abdominal cavity, such as colon cancer, small intestine cancer, stomach cancer, etc., the tumor will lead to the increase of permeability of blood vessels, which will further lead to the seepage of fluid in the abdominal cavity, which may be manifested as small intestinal interstitial effusion. 3. Hypoproteinemia: If liver cirrhosis occurs, or malnutrition occurs, it will lead to hypoproteinemia, and the fluid in the blood vessels will leak out, which may lead to small intestinal interstitial fluid. Small intestinal fluid is also seen in other causes, it is recommended to consult a doctor in a timely manner, under the guidance of a professional doctor to standardize the treatment, so as to avoid delaying the condition.