Final answer:
Surgery for a congenital umbilical hernia is advised if the hernia becomes incarcerated or strangulated, causes pain or bowel obstruction, or does not resolve on its own by 4-5 years old.
Step-by-step explanation:
When a congenital umbilical hernia is present, surgery should be advised in certain cases. The decision for surgery depends on the size of the hernia, the age of the patient, and the presence of any associated complications. Generally, surgery is recommended if the hernia becomes incarcerated or strangulated, causing pain or bowel obstruction. Additionally, if the hernia does not resolve on its own by the time the child reaches 4-5 years old, surgery may be recommended to prevent future complications.