All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The menstrual period has no exact limit for it could increase or decrease. Consequently, the blood which comes out immediately before or after the menstrual period is considered menstruation, unless it exceeds fifteen days. In the latter case, it is considered vaginal bleeding and the woman applies the rulings of non- menstruating women. Thus, she is required to observe prayer, fast Ramadan and do other acts of worship which a non- menstruating woman is required to do.
The yellowish or brownish discharge (described as a dirty-water-like fluid) which comes out before complete purity is considered menstruation. Purity here refers to dryness of the vagina completely which is known when a white cotton pad the woman uses has neither yellowish nor brownish traces on it. Wetness of the vagina is of no significance.
The yellowish or brownish discharge which comes out after purity is not considered menstruation. Nevertheless, it invalidates Wudhoo’ (ablution) and necessitates cleansing the vagina.