What Can Be Done To Cure The Unbearable Groin Pain Post Flu Making My Father Unable To Stand ?

My father is a pretty active 60 male with well controlled diabetes (no insulin).He has a history of prostrate problems, and high blood pressuren (both controlled my medications), and had a hernia removed last year. Two weeks ago he became down with the flu and had an exceptionally violent cough (he burst a blood vessel in his eye from coughing so hard), he was prescribed antibiotics and given oral sterioids--he is over the flu, Today, he awoke with unbearable groin pain on one side of his body--he could not stand on his feet. He has no fever, and is not nasuaseated.