Hi,my Father Had A Bypass Surgery On June 22.after That

Hi,my father had a bypass surgery on June 22.after that he had pus formation on July 20.Then he underwent resuturing.now the sutures were removed.but now he again got pus formation in a spot.after consulting doctors are saying its some skin tissue problem.please let me know how to proceed on this further.what medications we have to take to stop the pus??