Suggest Remedy For Constant Pain In The Middle Of The Buttocks

Hello! My mom is having a bit of trouble. Please help! She had surgery for an inguinal hernia about two weeks ago and now she is having a consitant pain in the middle of her buttocks. I have researched and researched but nothing has come up...please let me and her know if everything is normal and alright! She has done no lifting at all except some paper and no pulling/pushing. We really need to know what is going on. She put an ice pack on for 20 minutes but it didn't help anything. She says that it might be something with a syatic nerve...please help!