Is a woman required to fast and pray if a dark brown discharge appears after her menstrual period has ended and she has performed ghusl, or must she make up for that day? Does she need to perform ghusl again or is wudu’ sufficient? Is the supplication "I intend the purification from ritual impurity" sufficient for the intention?

If the discharge occurs after the usual end of menstruation or after seeing the signs of purity (ṭuhr), it is istihadah (definition) (non-menstrual vaginal bleeding), which necessitates performing ablution (wudu') for every prayer and allows fasting. However, if it occurs during the usual days of menstruation, it is considered menstruation (hayd) and prohibits prayer and fasting. There is no specific supplication (du'a) for purification from menstruation. The intention (niyyah (definition)) resides in the heart, and it is not legislated to utter it verbally.