He ﷺ also said about a person who is uncertain whether any wind has passed: “He should not leave [his prayer] unless he hears a sound or detects an odor.”

As for what leaves the body from other than the two private passages—such as blood, vomit, or a nosebleed—the scholars have disagreed over whether it nullifies wudu or not. There are two views, and the stronger opinion is that it does not; nonetheless, avoiding the point of dispute would be better.

2. Among the things that invalidate wudu is the loss or veiling of consciousness. Full loss of consciousness occurs through insanity and the like, while its veiling takes place through sleep, fainting, and similar states. Anyone whose consciousness is lost or veiled by sleep or something akin to it has his wudu broken, for this situation makes the passing of impurity likely while he is unaware. A slight doze, however, does not nullify wudu, for the Companions were often overtaken by drowsiness while awaiting the prayer. Only deep, engulfing sleep breaks wudu, in order to harmonize the various evidences.

3. Eating camel meat—whether a small or large amount—is also a nullifier of wudu, because an authentic and explicit hadith from the Messenger of Allah ﷺ states so.