I had a shocker run with thrush a couple of years back... in the end I only got rid of it by using probiotic capsules. Turns out I had a resistant strain so canesten did nothing, but sticking acidopholous capsules where they aren't normally meant to go cleared things up really quickly.

The other thing that really helped relieve things - washing in warm water with salt and bicarb soda added - I'm told that it changes the pH to be unfriendly towards the thrush - I was just interested in it helping me feel better.

BW