I always ate plenty of fibre and a lot of fruit and vegetables, as long as I can remember! "Food" to me meant all those healthy things, and I couldn't imagine eating anything else. But when IBS hit me (IBS D) I had to suddenly switch to more bland food, including "white" carbs with my meals instead of wholemeal or seed/grain, potato skins, etc. I also had to cut down quite a lot on my way more than five-a-day fruits &veggies usual habit.
It took me a while to understand that, and I kept trying to eat my usual foods. But it was when I got worse when I did, and my IBS became more manageable when I didn't, that I began to learn I had to start reversing things, no matter what "healthy diet advice" I was reading, or what general advice there is about diet.
Things did become a bit more manageable that way and over time I have been able to include more vegetables and occasionally high fibre foods once again. But it's a constant balancing act.
I know I haven't been able to eat any amount of mango for years, much as I love it, and can tell you I KNOW what would happen to me if I ate a whole one!
But if my gut is flaring up I will usually wake up too early with an uncomfortable morning feeling in my gut, like my gut just can't wait another couple of hours in order for me to have a full sleep. Like my body is on high alert.
I wonder if it's just the morning thing with you too? It's a natural time for most people for the body to be preparing to eliminate after we get up, only it gets speeded up and more dramatic with IBS?
Then of course the tiredness doesn't help either.