Mesenteric lymph node enlargement is an imaging description, but not a diagnosis of disease per se. The cause can be the normal development of the intestinal immune system in response to something or the intestinal environment, or it can be a viral infection causing mesenteric lymphadenopathy. The most important thing is to exclude other acute abdominal conditions such as intussusception, appendicitis, and some rare infections. The most common cause is a viral infection. The symptoms are abdominal pain, sometimes accompanied by symptoms of gastroenteritis, i.e. diarrhea and vomiting. If you are able to drink, try to drink as much water as possible to avoid dehydration. If you vomit even with water, you may need intravenous fluids. Most children will heal on their own within a few days. Sometimes pain medication is needed, and when you start eating again, start with easily digestible foods such as porridge or crackers. Random antibiotics are not recommended, and IV fluids are not recommended when the child is able to drink. Some parents ask, “How can I recover without medication?” Are viral infections common? A normal person’s immune system produces antibodies to fight off viruses. Children with low immunity sometimes need antiviral medication. The side effects are significant and more than one can damage the liver.