Infection is the most common cause of vaginitis.
When the vagina is irritated due to an infection, friction caused by intercourse usually makes the condition worse. Therefore, intercourse is not recommended until the infection has been treated. Vaginal dryness also can cause pain and irritation during intercourse. A lubricant such as K-Y Jelly or Replens can help reduce vaginal dryness. Although yeast infections are rarely spread during sex, the other four infections are sexually transmitted.