Is it obligatory to go to the mosque for prayer, or to wait and pray at home upon the emission of prostatic fluid (wadi) after urination, taking into consideration Ibn Uthaymeen's fatwa regarding waiting for urinary incontinence to stop?

If you are certain that going to the mosque will result in the emission of wady (pre-seminal fluid) and invalidate your wudu' (ablution), then you are excused from attending congregational prayers in order to maintain your purity. However, if it is merely a doubt, do not pay attention to it and do not fail to attend the congregational prayer.