Touching impure things does not break wudu, but if a person touches something impure, it is not permissible for him to pray until he has washed it off.

Passing wind breaks wudu but if a person passes wind continually, he has to do wudu for each prayer when he wants to pray, then if wind comes out of him whilst he is praying, that does not invalidate it.

Applying cream on the face does not break wudu nor does it break the fast.

Erection does not break Wudu if nothing comes out of the penis because an erection is not one of the things that invalidate Wudu.

Some of the scholars said that if water (pus) from wounds is a small amount, it does not break wudu, but if it is a large amount then it does break wudu.