What is the ruling on blood spotting from a woman's uterus while fasting, if the menstrual period has exceeded ten days, and the blood is due to internal uterine inflammation and is not menstrual blood (like a thin, short thread of wire, appearing once for one day and then stopping)?

This blood is not menstrual blood and does not affect the fast, nor does it necessitate abandoning prayer. Rather, it requires ablution for each prayer. Sheikh Ibn Uthaymeen was asked about the small spots of blood that continue throughout Ramadan (definition), and he answered that the fast is valid and that it is not menstruation but rather from the veins. The Permanent Committee was asked about the return of blood after the usual menstrual period has ended, and they replied that it is not menstrual blood but rather blood due to an ailment or corruption, and it does not prevent one from praying, fasting, or circumambulating the Kaaba. It must be washed off, and ablution is required for each prayer.