Praise be to Allaah.
The things that
invalidate wudoo’ are well known, and are mentioned in the answer to
question no. 14321. Touching
something impure is not one of them. But if a person touches something
impure, it is not permissible for him to pray until he has washed it off.
Shaykh Ibn Baaz (may Allaah have mercy on him) was asked:
What is your opinion concerning a doctor whose work sometimes
involves looking at the ‘awrah of the patient and touching it for the
purpose of medical examination? Sometimes when doing surgery the doctor has
to work in an environment that is filled with blood and urine. Is it
obligatory to renew wudoo’ in this situation or is it better to do so?
There is no sin in the (male) doctor touching a man’s ‘awrah
in cases of necessity or touching it for the purpose of treatment, whether
that is the ‘awrah at the front or the back. He may look at it or touch it
in cases of necessity. Also it does not matter if he touches blood if he
needs to during surgery, whether to remove it or to check on the state of
the wound. But he should wash his hands afterwards to remove whatever has
gotten onto them. Touching blood or urine does not invalidate wudoo’, but if
he touches the ‘awrah, whether at the front or the back, his wudoo’ does
become invalidated. But touching blood, urine or other impure substances
does not invalidate wudoo’, rather he has to wash them off.
Majmoo’ Fataawa Ibn Baaz,