Dr. Rif`at Fawzi, former professor of Shari`ah at Cairo Univ., states: “It should be clear that passing wind or touching the private parts during ghusl or wudu’ do not affect the validity of ghusl. They will invalidate wudu’ (ablution) but not ghusl. As for the issue if one is uncertain that they washed a certain part while doing obligatory ghusl, we’d like to clarify that if this happens while you are performing ghusl, you can simply wash that part to remove any uncertainty. However, if this uncertainty happens later after performing ghusl and wearing your clothes, then do not pay attention to such uncertainty or doubt.”