Nystatin is what I was on for about 2.5 weeks before my doctor cut it off, thinking he had treated me. Until then, I was actually making slow, but good progress. That was with the oral suspension (for treating thrush only). There are capsule and tablet forms that reach the gut, though they aren't strong enough to always get past the mucous lining there to get at where some the yeast is hiding.
Diflucan is much stronger, and is apparently hard on the liver, if taken longer than 2 weeks. Like a lot of things used for treating the yeast monster, your mileage will vary with the individual. I've heard so many mixed reviews here and elsewhere.