Bedpans are a mixed bag (pun intended). They can be awkward, uncomfortable, or fun.
If you are in hospital and cannot get out of bed and have an urge to poo, they are pretty much one of two options... use a bedpan or go on a Chux pad.
Most hospitals have two types of bedpan available, the "fracture" and the "pontoon". Here are pics:
https://www.ebay.com/itm/Vintage-Jones-Fracture-Bed-Pan-No-385-NIB/163709626594
https://www.ebay.com/itm/Vintage-Jones-Relax-Bed-Pan-Enamelware-Enamel-Bedpan-/184164421784
Those shown are vintage and are made of enameled steel, but modern plastic versions are common. the problem with either is they are uncomfortable to use and kill your back, even if the head of the bed is elevated while you on them. Also, it is by no means easy to poo on a bedpan, since your body is not positioned to "bear down". In my experience, unless you have the runs, some "help" is almost always needed to be able to poo... ie: a suppository or enema. A Dulcolax suppository or Fleet enema is the usually choice. Or lots of Colace.
There are more comfortable bedpans, such as this, available but are likely not available in hospitals:
https://www.ebay.com/itm/Bed-Pan-The-Most-Comfortable-Professionally-Recommended-Anti-Splash-Bed-Pan/173642969721
There are other problems with bedpans too. When one poos, the poo does not fall away as it does when sitting on a toilet, so one often ends up sitting in a pile of one's own poo.
Also, the capacity of bedpans is pretty limited. They will all hold the results of a Fleet, but have difficulty with a 2000ml enema, perhaps not during release, but a spill is likely when the bedpan is being removed. When expelling a large volume enema, you will be sitting in pooy water. That's certain.
The inflatable bedpans have problems of their own. For example, a sidewall can be compresses and the result is a mess.
I'm not saying you should not use a bedpan, but do be aware of the problems... it is certain to be a mess, especially with large volume enemas.
The alternative of pooing on a Chux can sometimes be a better option, especially if the help you get is about 500ml or less. This can include Fleets or a Lactulose enema. The person lies on their left side on several Chux pads, the enema is given, and the person stays left lying until the enema hjas worked. The pad absorbs the released liquid. It's actually a pretty good way of making someone poo.