Swelling & redness in navel area>oprsn.

My daughter in law is 31 yrs.She had undergone a gallbladder(removal) operation in May/16 by laparoscpoy.Again last Jan/17 she had to face another laparoscopy to remove her appendix.After a month of the operation there was redness around her navel with swelling and mild pain. She consulted another doctor who said sometimes due to some unsterilised instrument during operation it might be an infection.It mostly happens in laparoscopy. The doctor prescribed her Cifran-500 BD &Labrid-500 BD for 1 month.There was a bit relief in pain and redness.The doctor advised her to continue the same for 15 days further.Should she continue those antibiotics for such alonger duration? We have heard that the antibiotics are taken for 3-5 days.In hard cases antibiotics like Altocin/Erythromycin are given for 5 days or 7 days and 2nd.dose is repeated in an interval of 1-2 days Will those antibiotics not be harmful to her?