Is it obligatory for one suffering from urinary incontinence to perform istinja' and renew wudu for every prayer, and is it permissible for him to perform wudu a short time before the adhan to be able to complete congregational prayer or attend the Friday sermon from its beginning?

If the urinary incontinence is continuous most of the time, then one must clean oneself (istinja (definition)') and perform ablution (wudu') for each prayer after its time has begun. It is permissible to wait for the congregational prayer with the ablution after the time has begun, as long as the prayer time has not expired. However, performing ablution before the time of prayer begins is not sufficient.