 The local preference for dry sex causes women to introduce substances into the vagina to reduce lubrication, including leaves, tree bark, toothpaste and Vicks menthol rub.The WHO includes this practice within Type IV FGM, because the added friction during intercourse can cause lacerations and increase the risk of infection.Because of the smooth appearance of an infibulated vulva, there is also a belief that infibulation increases hygiene.