Dr. Marawan Shahin, Professor of Hadith and its Sciences, Faculty of Usul Ad-Din (Theology),Al-Azhar Univ. states: “Touching one’s sexual organ with the bare hand is among things that nullify wudu’. Also, touching another person’s sexual organs nullifies wudu’. Also, according to some scholars touching a non-mahram woman is among things that nullify wudu’. But we have to stress that there are different viewpoints among Muslim scholars whether touching all the above mentioned nullifies wudu’ or not. You can refer to books of Fiqh in this regard for details. In the case you have a certain substance you think that touching it may nullify wudu’ please mention it.

In addition, it should be clear that clothes are originally pure unless they are contaminated by an impure substance.

Impure substances may be tangible such as stool. You cannot pray wearing clothes bearing impure tangible substances unless you remove such substances by washing them. As for intangible things such as urine, you have also to wash them before going to Prayer in such clothes.”