hello, Thank you for your query Sounds like a hernia. An umbilical hernia that size usually does not need any treatment. Surgical correction may be advised if the defect in the abdomen (through which the hernia occurs) is big enough to cause worsening of the hernia and if risk factors (obesity, work related- having to carry heavy objects)is present. The surgery (not without risk, as is the case for all surgeries)has an excellent prognosis and minimal scarring as it is in the navel. An infection is possible but is usually associated with pain, redness, fever. I would clinically examine him, ask him to cough to see how big the hernia get. as for a CT scan to visualise the defect in the abdominal walla nd the structures in the herniated sac. Further course of action will be based on the above. Please ask him not to lift anything to heavy, especially above his head. Also to support this area with his palm pressed against it ,during a cough or sneeze. If any severe pain, vomiting, blood in stools, fever, go to the ER right away Hope this helps. please let me know if you need further clarifications. Wish you both good health