Hello, My Daughter Had And Was Treated For Strep One

Hello,
My daughter had and was treated for strep one month ago. Her only symptom was severe stomach pain. Her diagnosis was made via a rapid strep test. This month her symptom was severe stomach pain again, followed by several days of cramping and diarrhea. The rapid test was negative, but the one they sent out came back positive a few days later. She was put on amoxycillin the first time, but they are putting her on keflax this time. Should I be worried that she is not healing from the original bout with Strep?