What is the ruling on someone who performed ghusl but forgot to wash a limb, then went about their normal life; does he repeat the ghusl or wash only that limb, knowing that he suffers from scrupulosity (waswasa)? And what is the ruling on someone who intentionally swallowed water during ghusl and wudu'; does he repeat or complete it?

If one doubts the completeness of ghusl after finishing it, they should ignore this doubt, because it does not affect the validity of the worship after its completion. If one is certain that they forgot to wash a limb and a long time has passed, they should only wash the forgotten limb and not repeat the ghusl, because continuity (muwalat) is not a condition for the validity of ghusl according to the majority of scholars. Swallowing water does not affect the validity of wudu or ghusl, and one must ignore intrusive thoughts (waswas) and turn away from them.