Is it obligatory for a woman experiencing irregular bleeding (mustahaadah) to change her clothes before every prayer, by analogy with ablution?

A woman experiencing istihadah (non-menstrual vaginal bleeding) must be diligent about her purity. She should wash away the blood and plug the area with cotton or a cloth to stop or reduce the bleeding. If the bleeding does not stop, she should bind the area. Her ablution (wudu) and prayer (salat) are valid.

The Hanbalis hold that she is not required to repeat the ghusl (ritual bath) and binding for every prayer, while the Shafi'is maintain that she must repeat them if the binding comes loose or if blood appears from its sides. She is not required to change her clothes if she is certain of their purity.