Vaginitis is an inflammation of the mucous membrane of the vagina. Normally the vagina contains lots of ‘good’ bacteria which keep the mucous membrane healthy. However, if other bacteria enter the vagina they can disturb the good bacteria, leading to inflammation. The discharge (the fluid leaving the vagina) may be grey and have a different smell. Sometimes it may be painful to pee or have intercourse. You should visit your doctor if you suspect you have vaginitis.