DS waking to be changed *every* morning very early after pooing, won't go back to sleep, what can i do...?

[JustAQuickNap]

I'm not sure whether I should post this here or in Sleep, but I'll give both a go in case anyone anywhere has any bright ideas.

DS1 (2.7) wakes every night, anytime from about 5am onwards, asking to be changed as he's done a poo in his nappy. Inevitably he won't go back to sleep afterwards, which isn't so bad if it's nearer 6.30, but when it's 5am it's a real struggle for all of us.

He usually poos on the potty one or two other times during the day as well, often once before bedtime, but this doesn't seem to make any difference. I pretty sure that if he didn't poo at this time in the morning, he would stay in bed longer, but I'm absolutely clueless as to how I might encourage this to stop happening...or whether there's nothing at all I can do & we just have to live with these bonkers early morning.

Has anyone else experienced this?