Is it obligatory for one suffering from urinary incontinence to repeat istinja' if another event occurs during wudu', or is it sufficient to repeat wudu' only?

The ablution (wudu') of a person suffering from سلس (urinary incontinence or constant discharge) becomes invalid if another impurity (حدث) occurs, different from their常-occurring discharge, either during or after their ablution. They are not required to perform istinja' (ritual cleansing of private parts) to repeat the ablution, based on the opinion of those who do not deem istinja' necessary for every prayer.