What is the ruling on menstruation being interrupted after the fifth day and then continuing for another five days?

If a woman sees purity, she must perform ghusl. Then, if she sees blood thereafter at a time suitable for menstruation, she reverts to being in a state of menstruation. She must perform ghusl whenever the blood and any accompanying yellowish or brownish discharge cease, and she will be considered pure, as long as this occurs within a period suitable for menstruation (meaning the total days of bleeding and interspersed purity do not exceed 15 days). Any periods of purity that occur between the bleeding are considered valid purity.