I would like to know that when a person makes wudu, after wudu if he changes clothes, does he have to repeat the wudu again?
Changing clothes after you have performed wudu does not invalidate the ablution, therefore you are not required to repeat it again.
Wudu is invalidated only when:
1. Anything exits from the two private parts of the body.
2. Impure substances such as blood or pus flow from their point of exit and encroach on a place which it is incumbent to purify.
3. Vomiting, if it was a mouthful (this is determined by whether you were able to keep your mouth closed or not)
4. Sleeping lying down so that the rear is not firmly seated, or leaning [on one’s side] or reclining on something such that if it were removed he would fall.
5. Loss of consciousness through fainting or insanity.
6. Laughter in any prayer containing ruku` and sujud.
Allah knows best.
Answered by Mawlana Mohammed Kashif