Breathing in while pooping

Body: 

Does anyone tend to tighten their belly and breath in when pooping? It seems to help it come out and my lower belly has a tendency to automatically want to tighten up a bit but I am worried thats not good for the bladder, uterus, or rectocele (which is the problem i have). I try ti relax my belly but that lower area just really wants to tighten and with focusing onbrelaxing my bum it’s a lot to do at the same time. I am trying but really need some input in this.

Extra detail is that I am dealing with colon inflammation so pooping works a bit different, it was all diarrhea but now its more solid which has its troublesome episodes too and so my posture is basically my feet on a squatty potty but my thighs are almost parallel with the floor my knees are slightly raised, it makes it easier for me to relax my legs to poop and if I need to open my butt cheeks to help with lowering the pressure so the stuff will come out, it's easier for me to do so while trying to maintain some relax. Specially when its my body trying to poop out a one incher from the rectocele
My chest is pulled up and i try to maintain a lumbar curve.

I am working on putting my feet on the floor but it's a process and sometimes i just can't seem to relax enough. I feel like my toilet is too tall and thats part of why I can’t relax sitting there so I am thinking about getting a excercise step to allow me to not have to me so tippy toaed or super angled with my butt real high because that makes relaxing to poo impossible, ideas on if that is ok over a squatty pot?

When I get off the toilet I get on my hands and knees and do some breaths.

Here are a couple of reminder videos that include posture and toileting that are very helpful:

https://whole-woman.thinkific.com/courses/whole-woman-fundamentals

https://whole-woman.thinkific.com/courses/remember-to-remember

And, here is another one that discusses the importance of gut bacteria and its role in digestion and health:

https://whole-woman.thinkific.com/courses/whole-woman-lecture-series

It also includes a great video on vaginal health, as well.