After cutting appendix,it has to be caught in a forceps to bring it out or put it into a bag.
In this process,the appendix may be torn.
It can happen sometimes.
But,the cause of high fever
and chills is due to infection.
Pain is due to some fat getting adhered to incision site inside the abdomen.It may pull sometimes leading to pain.
Nothing to worry,use antibiotic like Cefuroxime
,anti inflammatory drug,anti spasmodic dicyclomine
wish you good health