The World Federation One Stop Fiqh

Ruling 506

If a woman’s nifās stops and she deems it probable that there is blood inside, she must perform ghusl as a precautionary measure and the ritual acts of worship, or she must perform istibrāʾ; it is not permitted for her to refrain from performing the ritual acts of worship without performing istibrāʾ. The method of performing istibrāʾ was mentioned in Ruling 495.