Reference: Fataawa Ramadhaan v2 p475 no.414
Fiqh al-‘Ibaadaat p196
Question: What is the ruling regarding blood coming out of the mouth, nose or any other part of the body of the fasting person?
Response: This [flow of blood] does not affect him because it occurred without him intending so. And if he had a nose bleed and a lot of blood came out, then his fast is [still] correct and nothing is required of him.
