Short answer
Ignore the doubt. A wudu you are sure you made is not broken by a doubt, only by certainty, such as hearing or smelling wind or seeing a drop. If doubts keep coming, scholars say you should not act on them at all. The four schools agree on this principle.
Certainty is not removed by doubt, so a doubtful breaking of wudu is ignored. A person with frequent doubts (waswasa) should disregard them completely. After istinja, it is recommended to sprinkle water on the underwear so that later dampness can be put down to that water.
The four schools agree on this.
Explanation
The Prophet ﷺ said that if you feel something in your stomach and are unsure whether anything came out, do not leave the masjid until you hear a sound or notice a smell. From this the scholars took a rule that runs through all of fiqh: certainty is not removed by doubt. If you know you made wudu and are only unsure whether it broke, you still have wudu.
Waswasa (intrusive whispering doubts) in purity is common and it is a test, not a sin. Practical steps scholars give:
- Act on certainty only. Unless you are sure enough to swear on it, it did not happen.
- Do not check. Looking at your underwear or feeling for drops feeds the doubt.
- Sprinkle water on the front of your underwear after istinja, so any dampness can be put down to that.
- Do not repeat wudu or prayer because of a doubt. Count your washes once, and if unsure, move on.
- Ignore doubts during prayer. Stopping a prayer for a mere doubt is not allowed.
Allah does not burden a soul beyond its capacity. If the doubts are taking over your life, it may be a form of OCD, and seeing a counsellor or doctor is part of taking the means. A qualified mufti can give you rulings fitted to your case.
Related: passing wind and urine leakage.
Ask a mufti about your own case. This answer explains the general ruling. When the details of your situation matter, as they do here, ask a qualified mufti and give them the full facts. Where to ask a scholar.
The evidence
Quran, Surah Al-Baqara 2:286
لَا يُكَلِّفُ ٱللَّهُ نَفْسًا إِلَّا وُسْعَهَا ۚ لَهَا مَا كَسَبَتْ وَعَلَيْهَا مَا ٱكْتَسَبَتْ ۗ رَبَّنَا لَا تُؤَاخِذْنَآ إِن نَّسِينَآ أَوْ أَخْطَأْنَا ۚ رَبَّنَا وَلَا تَحْمِلْ عَلَيْنَآ إِصْرًۭا كَمَا حَمَلْتَهُۥ عَلَى ٱلَّذِينَ مِن قَبْلِنَا ۚ رَبَّنَا وَلَا تُحَمِّلْنَا مَا لَا طَاقَةَ لَنَا بِهِۦ ۖ وَٱعْفُ عَنَّا وَٱغْفِرْ لَنَا وَٱرْحَمْنَآ ۚ أَنتَ مَوْلَىٰنَا فَٱنصُرْنَا عَلَى ٱلْقَوْمِ ٱلْكَٰفِرِينَ ﴿٢٨٦﴾
Allah does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned. "Our Lord, do not impose blame upon us if we have forgotten or erred. Our Lord, and lay not upon us a burden like that which You laid upon those before us. Our Lord, and burden us not with that which we have no ability to bear. And pardon us; and forgive us; and have mercy upon us. You are our protector, so give us victory over the disbelieving people."
Allah does not demand certainty beyond what a person can reach.
Sahih Muslim 362
Sahih... فاشكل عليه اخرج منه شيء ام لا فلا يخرجن من المسجد ...
"If he is unsure whether something came out or not, let him not leave the masjid until he hears a sound or notices a smell."
Doubt does not break wudu; only certainty does.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Taharah, nawaqid al-wudu. Doubt does not remove certainty; the one with waswasa ignores doubts.
- Nur al-Idah with Maraqi al-Falah, Chapter on istinja. Sprinkling water on the underwear to repel waswasa.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.