What is the ruling on one who doubts whether he recited Al-Fatiha in prayer, despite feeling that he did recite it?

If one doubts whether he recited Al-Fatiha or not, then if the doubt occurs within the same rak'ah, he should repeat the recitation of Al-Fatiha. If the doubt pertains to a previous rak'ah, he should nullify that rak'ah and add another rak'ah. If the doubt occurs after completing the prayer, it does not matter. This detail applies to natural doubt. However, if doubt becomes overwhelming and continuous, it should be disregarded.