Is continuity required when fasting for a مطلق vow, and is it permissible to interrupt it for a valid reason?

If someone vows to fast for an unspecified month and does not intend for the fasting to be continuous, then, according to the majority of scholars, continuity is not obligatory for him. He has the choice to fast for thirty non-consecutive days, or to fast consecutively. If he begins fasting from the beginning of the lunar month, he fasts until its end, even if it is twenty-nine days. But if he begins fasting during the month, then he must fast for thirty days.

However, if continuity is obligatory and an excused interruption occurs, then, according to many scholars, continuity is not broken if he resumes fasting immediately after the excuse is removed.