THINGS WHICH INVALIDATE OR BREAK WUDHU

An excretion of the penis, vagina or anus this would include urine, feces (Allah says, "...or one of you comes from relieving himself," thus proving that such an act obligates a new purification), and releasing gas from the anus.

Abu Hurairahreported that the Messenger of Allah said, "Allah does not accept the prayer of a person who has released gas until he makes a new ablution. A person from Hadhramaut asked Abu Hurairah, "What does releasing gas mean?" He answered, "Wind with or without sound." (Related by al-Bukhari and Muslim.) He also narrated that the Prophet said, "If one of you finds a disturbance in his abdomen and is not certain if he has released any gas or not, he should not leave the mosque unless he hears its sound or smells its scent." (Related by Muslim.)

Hearing the escaping gas or smelling it is not a condition for nullifying ablution, but he stressed that one should be certain of the action. As for al-Madhi (prostatic fluid), the Prophet said, "Make ablution." Concerning sperm or al-mani, said Ibn 'Abbas "It requires ghusl and for al-madhi and al-wadi, wash your sex organs and make ablution." This was related by al-Baihaqi in his Sunan.

Deep sleep that makes a person completely unaware of his surroundings  

If the person did not keep his bottocks firmly seated on the floor while sleeping, he must make a new ablution. Safwan ibn 'Asal said, "The Prophet, , used to order us while we were travelling not to take our socks off unless we were in post-sex impurity (i.e. not for defecation, urination or sleep)." (Related by Ahmad, an-Nasa'i and at-Tirmidhi, who graded it sahih.) If one's buttocks has remained firmly on the floor during his sleep, no new ablution is necessary. This is implied by the hadith of Anas who said, "The companions of the Prophet were waiting for the delayed night prayer until their heads began nodding up and down (from drowsiness and sleep). They would then pray without performing ablution." (Related by ash-Shaifi, Muslim, Abu Dawud and at-Tirmidhi.) The wording that at-Tirmidhi recorded from the chain of Shu'bah is, "I have seen the companions of the Prophet sleeping to the extent that one could hear some of them snoring. But, they would stand for prayer without a new ablution." Said Ibn alMubarak, "In our opinion, this happened when they were sitting."

'Aishah related that the Messenger of Allah, , kissed her while he was fasting and said, "Kissing does not nullify the ablution, nor does it break the fast." (Related by Ishaq ibn Rahawaih and al-Bazzar with a good chain.)

Evaluating its authenticity, 'Abdul-Haqq says, "I do not know of any defect in the hadith that could cause its rejection."

'Aishah also said, "One night, I missed the Messenger of Allah in my bed, and so went to look for him. I put my hand on the bottom of his feet while he was praying and saying,  'O Allah, I seek refuge in Your pleasure from Your anger, in Your forgiveness from Your punishment, in You from You. I cannot praise you as You have praised Yourself" (related by Muslim and at-Tirmidhi, who classified it as sahih.), and she also reported, 'The Prophet kissed some of his wives and went to prayer, without performing ablution." (Related by Ahmad and "the four, and its narrators are trustworthy.) She also said, "I would sleep in front of the Prophet, , with my feet in the direction of the qiblah (to him). When he made prostrations, he would touch me, and I would move my feet." In another narration it says, "When he wanted to prostrate, he would touch my legs."

Bleeding from an unusual place 

This involves bleeding due to a wound, cupping or a nosebleed, and regardless of whether the amount of blood is small or large. Said al-Hassan, "The Muslims still prayed even while wounded." (Related by al-Bukhari.) He also reported, "Ibn 'Umar squeezed a pimple until it bled, but he did not renew his ablution. Ibn Abi 'Uqiyy spat blood and continued his prayer. 'Umar ibn al-Khattab prayed while blood was flowing from him. 'Ibbad ibn Bishr was hit with an arrow while praying, but continued his prayers." (Related by Abu Dawud, Ibn Khuzaimah, and al-Bukhari in mu'allaq form.) 

Vomit

Regardless of whether the amount of vomit was great or small, there is no sound hadeeth that it nullifies ablution.

Of doubts whether or not one has released gas 

This is the case where the person cannot quite recall if he is in a state of purity or not. Such a state of mind does not nullify ablution, regardless of whether the person is in prayer or not, until he is certain that he has nullified his ablution. 'Abbad ibn Tameem related that his uncle queried the Prophet about a person who feels something in his abdomen while praying. Said the Prophet, "He should not leave (the prayer) until he hears it or smells it." (Related by Muslim, Abu Dawud and at-Tirmidhi). It does not mean that its sound or bad smell nullifies ablution, but that the person must be certain about the fact that he has nullified his ablution. Says Ibn al-Mubarak, "If one is uncertain about his condition of purity, he does not need to perform a new ablution." If one is certain that he has nullified his ablution and doubts whether he has purified himself or not, he must perform a new ablution.