Source: Fatāwā ʿUlamāʾ-e-Ḥadīth, Volume 09
Is it permissible to perform Wudu (ablution) and Ghusl (ritual bath) in a place where the bathroom and toilet are combined?
If the area is clean, then it is better to perform Wudu or Ghusl there. If not, one should first rinse the area with water to clean it. Once the place becomes clean, both Wudu and Ghusl are permissible there.
In modern times, flush systems are used, and they remove impurities effectively. Thus, after the impurity is removed, the area is considered clean, and one may comfortably perform Wudu or Ghusl there.
However, as a precaution, it is better to recite the supplications (duʿās) of Wudu outside of the bathroom.
