Hi ChambeRay, I don't know if that is strictly Endo related, but I definitely know that feeling. I think this maybe why women are so often misdiagnosed as having IBS instead of Endo?
From what I understand, which isn't much to be honest, if Endo nodules imbed themselves in the walls of the bowel or lower intestine, this can cause these sorts of pains, or at least contribute to them. The Endo cells swell as we go through our cycle, no matter where they are in the body. That swelling puts pressure on whatever body part they've attached themselves to, causing pain in random body parts.
Personally, I've got an added complication as I've had my gall bladder out and have ha massive vowel issues ever since. That's part of the reason it took me so long to go to a doctor; I blamed all my pain on not having a gall bladder and never thought it could be related to my period.
My experience is just like you described, although mine is almost daily, but not always as extreme. Some days are far worse than others. I get anywhere from 20 seconds to 5 minutes notice - the notice is the cramping starts. Then, when I go to the bathroom, as you said, it comes in waves, cramps that bring tears to my eyes and make me feel like I can't breathe, cramps that make period pains look easy. I sweat everywhere, but also seem to get really cold so I end up shivering while sweating. I also get really flushed through my face into my chest. (That can be a bit embarrassing at work as I can't hide the sudden rashy appearance of my skin.) After, I feel absolutely drained of energy, physically wiped. I have read somewhere why that is, but I can't remember exactly - something to do with our body releasing salts or something to try and stabilise the cramping muscles and that leaves one feeling fatigued? Don't quote me on that, but there is a justifiable medical reason why we feel so exhausted after one of those episodes.
When this happens to me, it usually keeps up, off and on, for about four hours, then it stops. I pretty much have to be within immediate access to a bathroom for four hours from the first attack because I'll have to go again every half hour to 45 minutes. It's like clockwork. Usually, past the first attack, not much comes out of me, just whatever was left, but the pain and all keeps up through every wave.
I don't have any answers for you, unfortunately, but I do know the feeling. You aren't alone in this. It happens to others too just the way you described it. Hang in there! ❤️