What Causes Vomiting, Diarrhea And Stomach Pain After Removing Gall Bladder?

My sister has had her gallblader taken out roughly 1 month ago. She went to dr. for extreme pain in her right side and stomach, vomiting, dihiara, and low grade fever. It has been a month since her surgery and all this is back again, it has been going on for 3 days. What to do?