Brief Answer:
Most probably an obstructed Umbilical Hernia.

Detailed Answer:
Hi.
Thanks for your query, albeit short and specific.
To recapitulate: Male/70 - Lump behind naval - hurt only on pressing ...
The commonest cause if an umbilical hernia, with an attached irreducible ball of fat.
There is nothing else that can cause similar finding.
You may please get this confirmed by the following:
Clinical evaluation by a General Surgeon by actually examining this.
High resolution ultrasonography to confirm the clinical findings and plan for further management if required.
Rarely CT scan may be required to rule out anything else and to be certain about the diagnosis.

I hope this answers your specific query, please feel free to ask for further relevant queries if you feel that there is a gap of communication.

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Brief Answer:
Get a clinical evaluation and investigations before going on a trip.

Detailed Answer:
If there are no symptoms of local pain, pain in abdomen, bloating, changed bowel habits, it may not demand immediate attention.
You may consult a Surgeon to make sure the diagnosis get necessary investigations, get an appointment for surgery if required and then can go on a trip.
I hope this answers your query.

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