What is the ruling on prayer if menstruation continues for twenty days, given that the first seven days are sticky brown discharge?

If a woman sees dark discharge during the time when menstruation is possible (after fifteen days have passed since the previous cycle), it is considered menstruation.

If the bleeding continues for more than fifteen days, the woman is considered to be experiencing istihada (non-menstrual vaginal bleeding). Menstruation is then determined by distinguishing the blood by color or odor: whatever possesses the characteristics of menstrual blood is considered menstruation, and whatever does not is istihada, which does not prevent worship.

If she cannot distinguish the blood, she acts according to her habit (her usual duration of menstruation), and the excess is considered istihada.

A woman experiencing istihada is treated as one who is ritually pure; she prays and fasts, and performs ablution for each prayer after its time has begun, along with washing away the impurity and binding the affected area.