Frequent diarrhea in 7-year-old children can be caused by bacterial infection, viral infection, improper diet, irritable bowel syndrome and other factors. 1. Bacterial infection: Bacterial infection in children, bacterial enteritis, can cause frequent diarrhea symptoms, can also be accompanied by fever and abdominal pain and other manifestations. 2. Viral infections: Children infected with rotavirus, norovirus and adenovirus can cause viral infections in the intestinal tract, which can cause diarrhea, nausea and vomiting, and drainage-like stools. 3. Improper diet: Eating cold, irritating, unclean food, or eating too messy diet can cause acute gastroenteritis and frequent diarrhea. 4. Irritable bowel syndrome: when irritable bowel syndrome occurs, due to the abnormal sensitivity of the intestinal nerves, there can be obvious diarrhea after the abdomen is cold or eating cold food. 7-year-old children with frequent diarrhea should be timely medical treatment, under the guidance of specialists actively line of appropriate treatment, help early relief of discomfort.