Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: The Prophet (peace and blessings be upon him) was asked about a man who feels during the prayer that his ablution has broken, although it has not. The Prophet (peace and blessings be upon him) said: "Satan comes to one of you while he is praying, until he opens his back passage, so the man feels as though he has incurred hadath (ritual impurity), although he has not. Whoever finds such a situation, let him not end the prayer until he hears the sound (of wind passing) with his ear or perceives its smell with his nose."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and al-Bazzar recorded something similar; the narrators of this narration are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1248