Must one make up for a prayer if, while making up consecutive prayers, one doubted whether one had stood up after reciting the Fatiha or after straightening up from bowing, and one considered it to be after bowing because one is prone to doubt?

Making up missed prayers is an immediate obligation, while observing their proper order. It is permissible to spread out the makeup prayers if making up many at once affects concentration. Thus, making up prayers is obligatory according to one's capacity and ability, in a way that does not harm the body or livelihood.

As for doubting the omission of a pillar of prayer during it: if a person is not prone to frequent doubts, then they must act upon certainty and perform the doubted pillar. However, a person who is prone to frequent doubts should not pay attention to their misgivings.