Why does your child always cry out for abdominal pain? Is it a trick to avoid going to school? Is it parasites, but the child has already taken worming medicine and is not getting better; is it enteritis, but the child’s appetite and bowel movements are normal? Is mesenteric lymphadenitis so difficult to treat? The child’s stomach pain and sometimes ultrasound examination of enlarged lymph nodes seem to be consistent with mesenteric lymphadenitis, this diagnosis is also in line with the child’s family psychology, however, this diagnosis is often incomplete. What are enlarged lymph nodes? Normal mesenteric lymph nodes are usually less than 7 mm, and ultrasound diagnosis of enlarged lymph nodes is based on different criteria, for example, CT generally considers a diameter of more than 1 cm to be the threshold for enlargement. On the other hand, ultrasound considers two or more lymph nodes in the same area of the mesentery to be enlarged, with a diameter greater than 10 mm in the long axis, 5 mm in the short axis, and a longitudinal to transversal ratio greater than or equal to two. What strongly suggests clinical significance lies more in the structure of the lymph nodes, e.g. a normal one would have parallel growth, smooth peritoneum, clear corticomedullary demarcation, visible lymphatic gates, and an aspect ratio of less than 1. Are enlarged mesenteric lymph nodes an indication of inflammation? The most common cause of mesenteric lymph node enlargement in children is mostly reactive enlargement, which is commonly caused by intestinal and extraintestinal diseases or infections, as well as external stimuli such as food allergy and food intolerance. After the primary disease is controlled and external stimuli are eliminated, the reactive hyperplasia and enlargement of mesenteric lymph nodes will return to normal, which means that the enlargement is not always inflammation. Inflammation is often characterized by “redness, swelling, heat, and pain”, so lymphadenitis is unlikely in a child who has no fever, no history of an antecedent infection in the airways, non-persistent pain that resolves on its own, and a good general condition. Asking about the features of abdominal pain can help in the identification, because swollen lymph nodes are not necessarily inflammatory, so antibiotics are not always necessary. Abdominal pain is not always caused by this enlarged lymph node? Yes, it should be said that there are many causes of abdominal pain, including medical and surgical disorders, which can be pathologic or functional, but abdominal pain in children, which is generally good, is more likely to be a functional cause of intestinal cramps. The enlarged lymph nodes are related to the growth and development characteristics of children: small children are in the period of growth and development, the body’s immune system is active, immune function is strong, lymphatic follicle birth center is obvious; on the other hand, due to the children’s body development is not yet perfect, a variety of stimulating factors may stimulate the lymph nodes enlarged. However, this enlarged lymph node is not necessarily the cause of abdominal pain. Some people say that abdominal pain is also a kind of “growing pain”? Yes, there is such a thing. This abdominal pain type “growing pains” is the essence of intestinal spasm, can not be said to be a disease, more accurately said to be a growth phenomenon, most often seen in the growth period of the child, that the mechanism of this situation mainly lies in: rapid growth and development of children, so that the body’s blood supply is caused by a temporary shortage of blood in the intestinal tract in the temporary ischemic state, there will be intestinal spasm contraction. The intestinal tract, in a state of temporary ischemia, will experience intestinal spasmodic contraction and cause abdominal pain. In addition, abdominal pain can also be caused by plant nerve dysfunction, resulting in uncoordinated gastrointestinal nerve inhibition. Therefore, for children with abdominal pain and enlarged mesenteric lymph nodes indicated by ultrasound, clinical attention should be paid to finding and analyzing the causes of enlarged mesenteric lymph nodes, including intestinal diseases and extraintestinal diseases. And after standardized treatment, if the enlarged mesenteric lymph nodes do not retract or even increase in size, the original diagnosis should be reviewed to avoid missed diagnosis and misdiagnosis.