I'll add my voice to the "bad douche! no!" crowd.
The chemistry "down there" is an extremely delicate balance of wee beasties and acids and sugars and stuff, and if you throw it off by douching you can start a vicious cycle by which the douching creates more problems that are relieved to some extent by douching, which creates more problems, which are relieved by douching, you get the picture.
Now, a good bidet...that's another thing
If you've got the itchies, try Raeanna's acidophilus suggestion. You can buy a supplement called "yeast busters" at most health food stores. Also try cutting back on simple sugars, and drink as much cranberry juice as you can stand - the kind that doesn't have corn syrup in it. Sometimes bacterial infections can mimic yeast infections, and can come and go and come and go - you can pass it back and forth to your partner, as it turns out. If you've got something that's persistent, it can't hurt to have a doctor check it out to make sure it's not something serious.