All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The Maalikis held that if the Hadath (ritual impurity: passing urine, stool or wind) lasts half of the time or most of it, it does not invalidate ablution.
The Maaliki book Sharh Ad-Dardeer combined with Sharh Mukhtasar Khaleel reads, "The state of purity is invalidated by incontinence that stops most of the day and occurs in a short part of it, but if the incontinence lasts half or more than half of the day or all of it, it does not invalidate it."
Haashiyat Ad-Dusooqi ʻala Sharh Ad-Dardeer reads, "The author referred to incontinence in general, so it includes incontinence of urine, stool, wind, and other forms, such as incontinence of semen, Mathi (pre-ejaculatory fluid), and Wadi (white penile secretion usually discharged after urination). This is why he said in the explanation that this applies to all forms of Hadath."
Regarding the evidence of the Maalikis, the Maaliki scholar Al-Baaji wrote:
"... Any discharge that is beyond the person's regular habit, to the extent that it becomes difficult to avoid, falls under the heading of the excused incontinence. (Imaam) Maalik underlined that the incontinence of semen, Mathi, or urine does not invalidate ablution, contrary to the view of Abu Haneefah and Ash-Shaafiʻi. The evidence for what we are saying is that this is a fluid that necessitates purification if it comes out in the normal manner, and if it does not come out in the normal state, it does not necessitate such purification, such as menstrual blood. Al-Qaadhi Abu Al-Hasan said that if a woman frequently experiences non-menstrual vaginal bleeding, she is required to perform ablution each time (before performing an act of worship that requires ablution); but if the bleeding recurs and lasts for hours, it is only recommended for her to perform ablution each time." [Al-Muntaqa]
The Maaliki scholar Khaleel wrote, "The evidence for the main view (of the Maaliki school) is that obliging the person to repeat the ablution while he has recurring incontinence constitutes hardship, and hardship should be removed in religion." [At-Tawdheeh]
Shaykhul-Islam Ibn Taymiyyah wrote, "The continuous state of impurity, such as non-menstrual vaginal bleeding and urine incontinence, does not invalidate ablution unless the person also experiences what is normal. This is the default opinion of Maalik." [Al-Fataawa Al-Kubra]
Allah knows best.