Suggest Remedy For Pain With Reddish Skin And Swelling

hello, doctor,my father's age is 62,and 5'6". and slim body.he has no any problem but he had hernia & doctor had done operation before month
my father has so much pain & reddish skin & swelling on skin after hernia operation so please please tell us what to do.one month completed of his operation.doctor prescribed medicines but it cant work.so any exercise or he has to change his body position when he sit or sleep or any help regarding this please help.thank you
Rina