Firstly: Defining Istihadah
Istihadah linguistically: is blood exiting from the woman after her habitual menstrual cycle from a vein known as `adhil, which is different from that of menstrual blood.
Istihadah technically: is the outpouring of blood outside its time from the lower part of the womb as opposed to its inner.  Jurists predominantly use the term to describe the outpouring of blood after the days of menstruation, or if bleeding exceeds the maximum days of menstruation.
Secondly: The Nature of the Blood from Istihadah
The nature of istihadah is that it is thin, red, liquid without a foul smell that dries once it appears.
Thirdly: The Discerning Woman with Habitual Menstruation Who Has Istihadah
The woman who knows her cycle’s habits acts upon that, not her discernment. This is the position of the Hanafis, Hanbalis, a valid position Shafi`is, seen as most apparent by Ibn Taymiyyah, and chosen by Ibn `Uthaymin.
Fourthly: The Non-discerning Woman with Habitual Menstruation Who Has Istihadah
The woman who has a habitual cycle follows its normal length, then washes and starts praying again. This is the position of the majority: Hanafis, Shafi`is, and Hanbalis.
Fifthly: The Discerning Woman without Habitual Menstruation Who Has Istihadah
The woman who can discern between menstrual and istihadah blood but does not have a habitual menstrual cycle acts upon her discernment. This is the position of the Shafi`is and Hanbalis, and the choice of Ibn Taymiyyah, al-Shawkani, Ibn Baz, and Ibn `Uthaymin.
Sixthly: The Non-discerning Woman without Habitual Menstruation Who Has Istihadah
Whoever does not have the ability to discern between the different types of blood nor has habitual menstruation follows what the majority of women follow, such that her cycle becomes six or seven days from every month which start from the first sight of blood and anything other than that is istihadah. This is the position of the Hanbalis, a position among Shafi`is, as well as being the choice of Ibn Taymiyyah, Ibn Rajab, Ibn Baz, and Ibn `Uthaymin.
Seventhly: The Rulings of The Woman Who Has Istihadah The difference between the rulings of menstrual blood and istihadah
The blood of istihadah does not take the same ruling as menstrual blood, and does not prohibit what menstrual blood prohibits. Consensus has been quoted over this by: Ibn Jarir, Ibn al-Mundhir, al-Marghinani, al-Nawawi, Ibn Taymiyyah, Ibn al-Qayyim, and al-`Ayni. Istinja’ at the entering of every prayer
The woman who has istihadah does not have to perform istinja’ at the entering of every prayer. This is the position of the Malikis, a position among Shafi`is, a narration from Ahmad, and the choice of Ibn Rajab and Ibn `Uthaymin. The ablution of the woman who has istihadah
The woman who has istihadah does not have to perform ablution at the entering of every prayer. This is the position of the Malikis, Zahiris, some of the Salaf, and it is the choice of al-Shawkani and Ibn `Uthaymin. The obligation for the woman to take means to clean herself from blood
The woman who has istihadah must clean her body from the blood.  A woman experiencing istihadah for instance would press and squeeze her private part, and one with urinary incontinence or abundant involuntary pre-seminal fluid would do the same with their penis, making sure as much of the najasah has left their body prior to purification. If it were something that cannot be pressed or squeezed like a cut on a flat bit of skin, or a varicose vein that cannot be drained, then the person afflicted with this would pray according to their situation. This is the position of the majority: hanafis, Shafi`is, and Hanbalis. If blood exits after rigorous measures
If the woman has taken the necessary and rigorous means to allow all blood to leave her body, like pressing her private parts and the like, but still after that blood exits, then it does not harm her purity. This is by agreement of the four schools of jurisprudence.  For the Shafi`is, ablution upon such a scenario only allows for one prayer to be performed, regardless whether it is in its time or made up. The ritual washing of a woman who has istihadah
The woman who has istihadah does not have to perform ritual washing for any prayer, exept the one time she needs to do so for her purity from menstrual bleeding. This is by agreement of the four schools of jurisprudence. Intercourse with a woman who has istihadah
It is permissible to have intercourse with someone who has istihadah. This is the position of the majority: Hanafis, Malikis, Shafi`is, a narration from Ahmad, the position of a group from the Salaf, and the choice of Ibn Hazm.