Nystatin is relatively ineffective (only 60%) and I don't really understand why it is still prescribed. Diflucan isn't much better and it has to be taken in very large doses (200 mg for loading dose, 150 mg for 14-21 days following) and many doctors won't give you that much less insurance cover it. It is very helpful to cut certain foods from your diet, almost imperative, for about 3-4 weeks to that the bacteria don't have anything to thrive on. Eliminating all dairy, sugar (and sugar subs), most fruit, white flour, corn gives your gut a chance to heal and get rid of the bacteria causing the thrush and takes away the foods it lives on. You can have all the chicken, oats, vegies, rice, fish you want but thrush feeds on sugar, white flour and starchy foods. You should also try gentian violet which you can get at any health food store and most pharmacies. It is purple and stains but it works! Use it once a day on yourself and in baby's mouth for 4-7 days. Most cases clear in 4 days but may take as long as 7 but if it takes longer it is probably something other than thrush. If you haven't seen a lactation consultant you might want to especially if it doesn't clear up.