What are the things that do not invalidate and break wudu?
1 – If blood comes out from the private parts or somewhere else and it remains where it is without diffusing, it does not invalidate wudu. It does not matter whether that blood is wiped with the hand or cotton.
2 – Blood clot, flesh or skin falling off the wound without any flow.
3 – Touching the private parts. It does not matter whether they are the private parts of women or men. Only touching them does not invalidate wudu.
* According to Shafiis, if a man or woman holds the front or back private part of himself/herself or somebody else with the palm of the hand, his/her wudu is invalidated.
4 – Touching any part of a woman except her private parts does not invalidate the wudu of a man. However, if wetness called madi comes out as a result of touching due to excitement, wudu is invalidated.
* According to Shafiis, if a man touches a non-mahram woman, his wudu is invalidated. If he touches a mahram woman, his wudu is not invalidated.
5 – Vomiting less than a mouthful.
6 – Spitting out phlegm... According to Imam A’zam and Imam Muhammad, the amount of phlegm does not matter.
7 – Sleeping while sitting without losing the control of oneself. Like sitting on the bottom firmly and sleeping...
8 – Crying does not invalidate wudu; laughing does not invalidate it, either, except while performing prayers.
9 – The blood sucked by insects like fleas, ticks, mosquitoes and flies as much as they are full.
10 – Smiling while performing prayers.
11 – Trimming the mustache, having a hair-cut, trimming nails.
12- If a person knows definitely that he has made wudu but hesitates if he has broken it or not, his wudu is invalid according to Malikis but valid according to the other three madhhabs.
It is better to be cautious about the issues that are controversial whether the wudu is invalidated or not. It is an appropriate act for imams to be careful about the issues that invalidate wudu according to other madhhabs though it is not obligatory.