Can a person with urinary incontinence perform ablution after the cessation of urine flow and pray more than one prayer with a single ablution, so long as their ablution is not invalidated by another event? Is it sufficient to remove the pus from a pilonidal sinus with tissues without water? And is it obligatory to repeat the prayer if pus is discovered after completing it?

May Allah grant you healing and well-being.

Firstly: As long as the drops of urine cease for a period sufficient for purification and prayer, you must wait for this period to purify yourself and pray, even if you miss the congregational prayer. For prayer with valid purification takes precedence over congregational prayer. And if you perform ablution after the cessation of urine, your ablution is not invalidated except by the known invalidators, and not by the passage of time. So you may pray with this ablution as much as you wish.

Secondly: If you are afflicted with سلس (urinary incontinence), your ablution is not invalidated by the passage of time if nothing exits from you, and you may pray with this ablution as much as you wish.

Thirdly: Pus exiting from inside the anus invalidates ablution. If it is continuous, its ruling is the same as that of سلس (incontinence). As for what exits from outside it, it is not an invalidator, and there is a difference of opinion regarding its impurity. If it is considered impure, then its removal with water is obligatory. And if you wish, you may adopt the opinion of its purity for ease.