Answered by: Alimah Nasima Umm Hamza
I have a question regarding cleanliness. I am suffering from semen leakage problem for a long time. The problem is I cannot remain pure during the time of prayer as the semen leaks without any control and sometimes without any lust or with lust. I have tried lots of medications but it did not help that much.
1. Will I be in the category of Mazhur people by having one ablution for each prayer?
2. Sometimes, during prayer, I get lust unexpectedly which also increases semen leakage. In such cases, do I need to renew my ablution?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
A person is considered legally excused (ma’zhur) when he suffers from an ailment which prevents them to keep wudu long enough to perform even the minimum salah.
For you to be considered ma’zhur you would need to be unable to do wudu and remain pure for the few minutes required to perform fard salah. This must be the case for the whole timing (waqt) of the prayer time. If you, therefore, get to the end of the waqt for one salah time, unable to pray without any mazhi leaking, you will now legally be considered to be ma’zhur. You would be permitted to pray any fard and sunnah/nafl prayers in that timing and renew your wudu for the next prayer duration. This ruling will continue so long as you have at least one occurrence of leaking in every consecutive prayer thereafter. If you cease to have at least one occurrence of leaking then you will no longer be considered to be ma’zhur anymore. Then you would need to meet the conditions of ma’zhur a new. 
Please note: If you are able to make wudu and it long enough to pray the minimal fard salah, then you will not be considered to be ma’zhur.
Secondly, in the case where you are considered ma’zhur then the ruling will only apply to the involuntary leakage of fluid. If you were to have any other type of hadath (i.e. nullifier of wudu e.g. passing urine/wind, or passing madhi/wadi) then you would need to renew wudu again. In the case where you experienced lust in salah and then had leaking of fluid, it would no longer be considered involuntary passing of liquid, therefore you must renew you wudu and continue your salah.
Only Allah knows best.
Written by Alimah Nasima Umm Hamza
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Raddul Muhtaar, Volume 1, Kitab at-Taharah, Chapter on Ahkaam al-’Uzr, p.306