Hello,
There are some reasons for recurrent
thrush infection. These include when symptoms may not be due to
thrush, when
thrush is caused by other strains of Candida spp. such as Candida glabrata( These may not be so easily treated with the usual anti-thrush medicines), you are taking antibiotics, or if you have undiagnosed or poorly controlled diabetes.
You should get a fungal culture of vaginal discharge done and all these causes ruled out.