• Bacterial vaginosis – the most common vaginitis.  Caused by a shift in the balance of vaginal bacteria with less of the normal healthy bacteria and more of the type that may produce odor and discharge. Maybe recurrent and difficult to cure. Risk factors include douching, cigarette smoking, or a new partner.  However, Treatment of male partner has NOT been shown to be helpful.  Bacterial Vaginosis – CDC summary
  .
• Candida albicans – this fungal organism most commonly causes itching and irritation of the vaginal opening. Recurrences may be caused by recent treatment with antibiotic therapy, uncontrolled diabetes, pregnancy, disorders of the immune system, corticosteroid therapy, vaginal douching.
• Trichomoniasis – also called “trich”   – (sexually transmitted) and caused by a  single-celled protozoan parasite Trichomonas vaginalis. Produces marked odor. Treatment of male partner required.  Trichomonas – CDC Summary
• Atrophic vaginitis – the lining of the vagina becomes thin and fragile when estrogen levels drop around the time of menopause.  The vagina may become inflamed and irritated.  Effectively treated with local estrogen therapy (cream, tablets, suppositories, ring)

Cleveland Clinic Vaginitis Summary

WebMD Vaginitis Summary

In many cases, it is difficult to determine the cause of recurring vaginitis. However, you may be able to help yourself by paying attention to the following factors. If one of the following situations applies to you, you may experiment or change your activities in hopes of reducing the frequency of recurrent vaginitis. Please let us know if any of the following applies to you.
1. Antibiotic use
2. Pregnancy or birth control pill use
3. Stress, change in a sexual partner, known sexually transmitted disease exposure
4. Douching, vaginal medications over-the-counter
5. Tight, poorly ventilated clothing or Synthetic clothing such as pantyhose
6. Trauma (sexual intercourse)
7. Diabetes, AIDS (Immunocompromised)
8. Deodorant soaps, laundry detergents
9. Hot tubs or swimming pool chemicals
10. Vaginal contraceptives or bath oil use
11. Perfumed or dyed toilet paper use
12. Tampon Use
13. Oral sex
14. Intercourse with a man after he has been in the hot tub or swimming pool.

In some cases, one of the factors may be present but not causing your recurrences. In most cases, the only way to find out is to experiment by changing the factor or situation to see if it helps. Sometimes management involves prolonged treatment for initial clearance. Thereafter treatment at regular intervals even in the absence of symptoms is sometimes helpful in preventing recurrent outbreaks.