Allah does not accept the prayer of any of you who is in the state of Hadath (minor ritual impurity) until he performs ablution

The Prophet (may Allah's peace and blessings be upon him) clarified that Tahārah (ritual purity) is one of the conditions for the validity of prayer. Hence, whoever wants to pray must make Wudū’ (ablution) if he has already nullified his Wudū’ by defecating, urinating, sleeping, etc.

1. The prayer offered by one who is in the state of ritual impurity is not accepted unless he purifies himself by making Ghusl (ritual bath) in case of major impurity and by performing Wudū’ in case of minor impurity.
2. Wudū’ means rinsing the mouth with water and spitting it out, then sniffing water into the nose and blowing it out, then washing the face three times, then washing the hands along with the elbows three times, then wiping over the whole head once, and finally washing the feet along with the ankles three times.

صحيح البخاري (9/ 23) (6954). صحيح مسلم (1/ 204) (225). تيسير العلام شرح عمدة الأحكام، للبسام (ص17). تنبيه الأفهام شرح عمدة الأحكام، لابن عثيمين (1/ 11).