What is the reason for a six-year-old child's frequent pain around the navel?

Patient's question:

Patient gender: nu
Patient age: six years
Detailed condition and consultation purpose: Abdominal pain around the navel in children, accompanied by vomiting
Duration of the current illness: About ten days
Current general condition: Always feeling like vomiting
Medical history: None
Previous diagnoses and treatment history and effectiveness: None
Ancillary examinations: X-ray was performed with no findings
Others:

Doctor's answer:

Hello, it may be related to omphalitis. The treatment for omphalitis primarily involves washing with a 3% hydrogen peroxide solution and 75% alcohol, followed by applying 1-2% gentian violet, which can heal within a few days. Severe omphalitis should be treated by a doctor. It is also possible to be gastroenteritis. Have you undergone an abdominal ultrasound examination?