Why does my wife get white discharge after sex?

The increased secretions from the vagina during sex is a normal event. However, this occurs only for some time during sex and immediately afterwards. If she has whitish discharge for 2-3 days and she also has itching in her vagina, it might be indicative of (1) vaginal infection or (2) allergy to condoms (if you are using them). A detailed history and an internal examination of your wife is called for exact diagnosis of the problem. Please ask your wife to consult a gynaecologist.