The child’s stomach was hit by a person’s knee, ultrasound examination is fine, 3 days after the stomach still hurts, may be due to soft tissue damage, improper diet, cold and other factors. 1. Soft tissue injury: children’s stomach was hit with the knee, may be around the abdomen soft tissue caused some damage, so the ultrasound examination is fine, 3 days the phenomenon of stomach pain. 2. Improper diet, cold: children’s stomach pain may have nothing to do with trauma, may be children in the daily diet overeating, do not pay attention to regular diet, may lead to gastrointestinal dysfunction, abdominal pain phenomenon. Or when children do not pay attention to keep warm in their daily life, it may lead to cold abdomen, due to cold stimulation, it may lead to abdominal pain in children. The child’s stomach was hit with a knee, ultrasound examination is fine, 3 days after the stomach still hurts, may also be related to other factors, based on a symptom can not determine the specific cause, it is recommended to consult a doctor for examination in a timely manner.