My Daughter Is 19. She Has A Persistent Soar Throat,

My daughter is 19. She has a persistent soar throat, that is also partnered with the continual tonsil stones. She has rinsed with salt water, also mouthwash daily. But has continued to remove atleast one if not more tonsil stones from her throat on a daily basis. She has also changed her diet upon a doctors recommendation. What further step should I take to help her?