I really like the Coloclean system:
https://www.youtube.com/watch?v=nvLQb2KZuUE
Expelling with the system is much more like a closed system colonic and the pooing is somewhat different than on a toilet, but IMO it is a veey comfy way o be made to poo. The only down side is you kinda need a willing assistant fo te best experience.
I just love lying in bed with the speculum well up into me, balloon inflated, then being filled with the warm solution. When the enema works and the urge to poo becomes strong tere is no need to try and run to the toilet without leaking. You assistant has merely to release the clamp and you instantly start pooing into the waste bag.
The reason an assistant is a plus is to empty the poo bag and refill the solution bag for subsequent fill/poo cycles.
For enemas given with a bag, my choice is a good quality bedside commode, like this:
https://www.platinumhealthllc.com/products/ultracommode-voted-1-most-comfortable-bedside-commode-chair-soft-warm-padded-and-foldable-xl-seat-with-100-open-front-padded-pivoting-armrests-adjustable-height-free-commode-pail-blue
The seat is soft and I find it very comfortable. Shop around for best price. Partly filling the pail with water reduces the odors as does a poo deodorant spray.