Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Fatwa No.3785
Fataawa Ramadhaan – Volume 2, Page 480, Fatwa No. 423
Question: During one of the days in Ramadhaan, about fifteen minutes before Maghrib, I wiped my teeth with a tissue and some blood began flowing but I had not intended this. I have had this illness for some time and even when I brush my teeth with a miswaak (tooth stick), blood begins to flow as a result. Is my fast correct?
Response: Yes, your fast is sound. This blood that flows from your gums when you wipe them and when you brush them does not affect your fast.
And with Allaah lies all the success, and may Allaah send prayers and salutations upon our Prophet Muhammad ﷺ and his family and his companions.