What is the situation in which a woman must perform ghusl and pray after 15 days of menstruation if the blood or yellowish discharge connected to the blood continues for more than 15 days, and what is the difference between this and istihada and سلس ( سلس البول )?

The flow of blood or the discharge of yellowish fluid for a period exceeding fifteen days is considered istihadah (prolonged vaginal bleeding outside of menstruation). The woman must abstain from fasting, prayer, and all that a menstruating woman abstains from if the blood exceeds her usual period, or if it is accompanied by yellowish or brownish discharge. If the total period exceeds fifteen days, she should perform ghusl (ritual purification bath), pray, and make up for the prayers she missed. In the following month, she should only abstain for the duration of her usual period, or act based on valid discernment (of blood types), or abstain for six or seven days if she has neither a custom nor discernment.