Itching from the anal area is a sign of parasites (as well as yeast, which is also considered a parasite). Also, if your resistance is low, the anal area may be a hard place to heal up once there is an imbalance (and it sounds like there is). I have a friend who had a similar problem -- it was after many cleanses and she determined that she did not replenish the good bacteria and other things to her system so the overgrowth in that area was probably from that.
I agree with the suggestion to use tea tree oil (as suggested by s/o in a reply) but also try different things and listen to your own body. For example, you may need to shower-wash in that area twice daily for a little while and then ease into once a day. Also, make it a point to air out the area -- And with a little thought -- some 100% cotton underwear and the right loose slacks or skirt well it could create a healing environment. Further, experiment with creams/ointments and rotate products. You may need something strong in the beginning or at bedtime, or there may times the itching needs to be taken care of.
Some healing creams to try.
Aloe Vera: After a bowel movement, make an extra wipe with natural aloe Vera. It will keep the area extra clean and refresh.
Derma Gran: I think you need a prescription for this and I think elderly people use it a lot, but this ointment is a protectant that really covers the skin and prevents it from hurting, helps it to heal. However, it has aluminum hydroxide in it and this is not good to be exposed to it long term and they even suggest you apply this ointment with tissue or gloves.
Derma Gran BC: Similar to the ointment above, but with no aluminum!!! Really strong protectant.
Zinc Oxide: A tube of zinc sold at most pharmacies is great to have around. It is what surfers use for long-term sun protection -- and guess what? It may help a sore, inflamed anal area as well.
Diaper Cream: Try various creams to see what helps your body the most. I don't suggest Vaseline, but some mild cases and the right body type may do very well with petrolatum or petroleum jelly products.
Hydrocortisone 1% cream: Soothes the itching, could reduce inflammation, but do not use long term.
Some things to look out for:
Do you eat over-spicy foods? May need to break for a while?
Are you using the wrong soap? Get as natural as possible (plain ivory or Aveda suggested)
Too tight of jeans or clothes?
Wrong chair and do you sit crossed leg too much?
Do you wipe well? (Really, sometimes there is a tiny bit of excess that can irritate or bother an already irritated area)
Do you air out the area enough?
Are you using perfumed pads or liners? STOP! And get away from tampons...really.
How is your immune system?
(Don't over do vitamins ever, but when healing, it could help to take some C tablets that will help your healing. Also, from reading this forum, it sounds like because of Candida and other body yeast, it leaves us depleted in other things so there are other things you can take to enhance your immune system.)
Are you adding any good defensive stuff to your body? You'll need to research more and read through this forum, but there are things you can take to help fight this stuff -- like acidophilus, Three Lac, and so much more. I know acidophilus and pro-biotic are great to start taking.
Consider a parasite cleanse -- especially because the itchy symptoms are an indication of something - and I have read about it relating to parasites. Start with a Colon Cleanse and work from there. (Colonix?)
Lastly, be careful if you do go see the doc anyway -- nothing against doctors, but many are script happy and don't know much about yeast or parasites.
And be patient, it takes a while to first understand what is going on in our bodies and then to find out what we uniquely need. But with the right sleuth work, we will/can make steps towards better health.