What Does Severe Pain In The Upper Abdomen Indicate?

My daughter (age 40) had major surgery at St. Thomas Hospital in Nashville January 17 for a bowel obstruction caused by a ruptured appendix. She spent 8 days in the hospital and surgeon says surgery successful. Follow up visit said she was on track. Much difficulty with gas pain and diarrhea upon return home. Her internist eventually told her about an over the counter medicine for IBS which began to help immediately. She returned to work yesterday and for the first time in a long time seemed to feel decent. Today she started having severe abdominal pain which she says is located just below her breast area. She said she has not had pain this intense before. She is awaiting a call as I write from her surgeon but I wanted to see if I could learn anything online. I respect the Cleveland Clinic.