There are some things that make ablution invalid; such as any discharge from private parts and this applies to stool, urine, semen, blood and wind. Also Deep sleep and touching one’s private parts break ablution.
What invalidates the ablution
Ablution may be invalidated by any of five things, as follows:
1-A discharge through one’s private parts. This applies for any discharge of urine, stools, semen, blood or wind, of any amount. In the Qur’anic verse that mentions the situations when ablution becomes required for prayer,
:Allah says
‘if one of you has come from the toilet.’
(5:6)
With regard to a situation when one doubts if one has broken wind,
:the Prophet (peace be upon him) says that ablution is not required
‘unless one hears a sound or smells something.’
Related by al-Bukhari, hadith No. 137; Muslim, hadith No. 361
2-A discharge of impurity from any part of the body. If the discharge is urine or stools, it certainly invalidates the ablution.
3-Loss of the mental faculty, as in the case of sleep.
:The Prophet (peace be upon him) said
‘The eye is the string that ties the anal sphincter; when the eyes sleep, the string is loosened.’
Related by Ahmad, hadith No. 887; Abu Dawud, hadith No. 203; Ibn Majah, hadith No. 477
On the other hand, madness, drunkenness and loss of consciousness invalidate the ablution according to all scholars. Sleep that invalidates the ablution is deep sleep when the sleeper loses all awareness, no matter in what position one is asleep. Dosing off slightly does not invalidate the ablution.
The Prophet’s (peace be upon him) companions used to be very drowsy as they awaited
‘Isha’ prayer, and then they would stand up and pray without performing a fresh ablution.’
Related by Muslim, hadith No. 376
Many scholars consider that if one sleeps seated in a way that does not allow breaking wind, one’s ablution remains valid.
4-Touching one’s private parts directly, without cover.
:Busrah bint Safwan reported that the Prophet (peace be upon him) said
‘Whoever touches his private part should not offer prayers until he has performed the ablution.’
Related by Ahmad, hadith No. 887; Abu Dawud, hadith No. 181; al-Tirmidhi, hadith No. 82; al-Nassa’i, hadith No. 82
5. Eating camel’s meat.
:Jabir ibn Abdullah said: the Prophet (peace be upon him) was asked
“Should I do wudoo’ after eating camel meat?” He said, “Yes.” The person said: “Should I do wudoo’ after eating mutton?” He said, “If you wish.”
(Narrated by Muslim, 360)