Is re-ghusl (ritual bathing) required after the discharge of clotted brown, black, and red blood immediately following ghusl from menstrual blood on the sixth day, knowing that the menstrual cycle does not exceed six days and istihadha (non-menstrual vaginal bleeding) has not occurred before?

Any blood a woman sees during her menstrual period is considered menstruation. If she becomes pure and then the blood returns within fifteen days (the maximum duration of menstruation), this blood is considered menstruation, and she must refrain from prayer, fasting, and the like. When it stops, she must perform ghusl (ritual bath), unless it exceeds the maximum duration of menstruation, in which case it is considered istihadah (non-menstrual vaginal bleeding).