She did not know the ruling on the discharges that women experience, and she offered several prayers with one Wudu – what should she do?

Praise be to Allah.

These discharges and secretions that women experience are described by the scholars as moisture of the private part. They are light secretions that a woman may not feel, and women vary in the amount of discharge. 

The most correct view is that they are taahir (pure), because there is no evidence to indicate that this moisture is najis (impure). 

Based on that, it is not required to wash off whatever of that discharge gets onto the body or clothes. 

See the answer to question no. 44980

With regard to the ruling on whether it invalidates Wudu: 

Ibn Hazm (may Allah have mercy on him) was of the view that this moisture does not invalidate Wudu. 

However the majority are of the view that they do invalidate Wudu, unless they are continual, in which case she should do Wudu for each prayer when the time for it begins, then it will not matter if there is any secretion of moisture after that. The ruling on the woman who experiences that is the same as the ruling on those who have excuses, such as one who is suffering urinary incontinence or istihaadah (irregular, non-menstrual vaginal bleeding) and the like. 

Some of the scholars are of the view that the one who is affected by ongoing invalidation of Wudu is not required to do Wudu for each prayer, unless it is invalidated by something other than the issue that is ongoing in his case. Apart from that, it is mustahabb for him to do Wudu but it is not obligatory for him. Ibn ‘Abd al-Barr said: Wudu in this case, according to Maalik, is mustahabb (encouraged) but not obligatory. 

He said: Among those who said that Wudu is not obligatory for the woman who is suffering istihaadah were: Rabee‘ah, ‘Ikrimah, Maalik, Ayyoob and a number of others.

See: at-Tamheed, 16/98; Fath al-Baari by Ibn Rajab, 2/73 

This view is the one that Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) settled on.

See: ash-Sharh al-Mumti‘ ‘ala Zaad al-Mustaqni‘, 1/503 

Even if we assume that it does invalidate Wudu, according to some scholars, if you were unaware that these discharges invalidate Wudu and you offered a number of prayers with one Wudu, you do not have to repeat what is past, according to the more correct opinion, because you are excused, as you did not know. 

See also the answer to question no. 102504 

But in the future, it is better for you to do Wudu for each prayer, so as to avoid an area where there is a difference of scholarly opinion. One should try to be on the safe side in such cases, because according to the view that Wudu is required, acts of worship are rendered invalid if that is not done. Even those scholars who did not say that it is obligatory stated that it is mustahabb (encouraged). 

And Allah knows best.