What is the ruling if the distinguishing signs (color/odor) are intermittent or do not meet the minimum duration for menstruation?
Chapter on Menstruation
Al-Mughni
Book of Purification
Primary text
If a woman sees ten days of red, then five days of black, followed by continuous red, the ruling is similar to the previous case. If the black blood is continuous and exceeds the maximum duration of menses, she has no established distinction, and her menses is determined by the black blood because it most resembles menstrual blood. If she sees black blood for less than one day, she has no distinction because black blood cannot constitute a menses due to being less than the minimum duration for menstruation.
Supporting text
If she sees only red blood in the first month, black blood for five days followed by continuous red in the second and third months, and continuous red in the fourth month, she refrains during the certainty period of the first three months, the days of black blood in the fourth month, and five days in the fifth month because she has now established a habit (mu'tadah). Al-Qadi states she only refrains for the certainty period in the fourth month, unless the habit is established by two occurrences.