Ceazar,
Your Dad should go have it checked out by the folks who inserted it. It could be that it's too tight and it can be relieved (depends on the procedure of placement) or it could be that it's an infection brewing. I had one and was in the hospital for 4 days - he is immuno-commpromised so it could very well be an infection. Get it checked! It looks like the peg was placed at least 6 weeks ago - there should be no discomfort at all by this point.
Good luck - take care!