Because Muslims address God directly without an intercessor such as a priest, they believe they must purify themselves through ritualistic bathing before approaching the divine. There are major and minor causes of physical impurity, requiring different rituals to correct and cleanse.
Muslims strive for a purified state called tahara before they can pray. Minor bodily infractions include passing gas, urinating and defecating. A Muslim who has done any of these things must take part in a washing ritual called Wudu before he can speak to God. This ritual involves the cleansing of specific body parts.
Major causes of physical impurity include ejaculation for men and the passing of menstrual blood for women. A complete body cleanse called Ghusul is then necessary before praying.