When should a woman perform Ghusl after her menses?
6-3-2012 | IslamWeb
Question:
If a woman whose monthly cycle ends within the 7 days, then should she wait for 24hrs before performing ghusl? For example, the bleeding stops on Tuesday Fajr time, but there is still a discoloured discharge, then is it permissible for her to wait for 24hrs, so Wednesday Fajr she will start to pray.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
First, we would like to mention the statements of the scholars concerning the distinction between the yellowish and brownish discharges and the normal vaginal discharge. The author of Sharh An-Nihaayah says, “The yellowish color (of blood) is among the colors of the blood when it is thin. It was also said, "It is like the egg yolk or the yellowness of the silk worm." Besides, the book of Qaadhi Khan reads, ‘The yellowish color is like the color of figs (when they begin to ripen).'"
As regards the brownish discharge, then the scholars 
say that it is brown water that resembles dirty water.
Therefore, if you see a discharge of this kind, then it is considered yellowish or brownish discharge, otherwise it is from the moisture of the vagina.
Hence, if the colored discharges that you see (which you mentioned in the question) are yellowish or brownish discharges –according to the details that we mentioned above – then it is considered part of the menses if this is during the time-period of the monthly menses or they are connected to the menses. If the bleeding stops and the brownish discharge continues to come out, then you do not have to pray, as you should consider yourself as being in menses until you see the sign of attaining the state of purity, with either of its two signs.
Moreover, you should not hasten just because the blood stops until you see the sign of purity (white discharge). Indeed, women used to send a box with a piece of cotton with yellowish discharge to ‘Aaishah 
and she would tell them not to be hasty and to wait until they saw the white discharge, which signified being pure from menses.
If a woman sees the sign of attaining purity from menses after her regular monthly period, either by seeing a white discharge or dryness (i.e. the stoping of bleeding), then she must perform Ghusl (ritual bath) and pray and it is not permissible for her to delay the Ghusl and prayer.
The Encyclopedia of Fiqh reads, “Purity from menstruation is achieved by either of the two following matters: either by the stopping of the blood, or seeing the white discharge. What is meant by the stopping (interruption) of blood is dryness such that a piece of cotton comes out without being stained (discolored) with blood, or with brownish or yellowish discharge. Thus, the piece of cotton should be dry from all of this, and being wet with the moisture of the vagina does not matter. The white discharge comes out from the vagina at the end of menses.
On the other hand, the Hanafi and Shaafi'i school of jurisprudence stated that what should be taken into account is the cessation of the bleeding, if the bleeding is interrupted (stops), then she becomes pure; this is whether or not the white discharge comes out. However, the Maaliki School differentiated between the woman who usually becomes dry after menses and the one who usually has a white discharge after menses, and the one who usually has both a white discharge and dryness.
If the one who usually becomes dry sees a white discharge first, then she does not have to wait for dryness, and if she sees dryness first, she does not have to wait for the white discharge.
As regards the one who usually sees a white discharge only –or along with the dryness- if she sees dryness first, then it is desirable for her to wait for the white discharge to appear until the end of the desirable period of time (for performing the prayer). In case she sees the white discharge first, then she does not have to wait for anything after it. This is because the white discharge is more conclusive for the one who usually has it, and for the one who usually has it along with the dryness."
Similarly, if a woman sees the signs of attaining purity before the end of the regular duration of her monthly menses, she should perform Ghusl and pray, whether she sees this sign by the white discharge or by the dryness.
Nonetheless, some scholars are of the view that if a woman sees dryness during the duration of her regular monthly menses, she may wait for a day and half day after seeing dryness.
However, the view we adopt here at Islamweb is the first view, which means that she should perform Ghusl and pray immediately after seeing the sign of purity. As Ibn Abbaas 
said, "It is not permissible for a woman to wait for one hour after she sees the purity but to perform Ghusl (i.e. immediately after seeing purity)."
For more benefit, please refer to Fataawa 135041, 94252 and 127629.
Allaah Knows best.