Hi again Cheryl, yes, this can be a problem, especially when starting out with enemas.
So my suggestion is if you are taking the enema by yourself, make yourself comfortable in the bathroom by laying on your back with your feet pulled back so your knees are raised.
Start out with just a small amount of water at first, perhaps a pint. See how that works for you. If you are able to take a pint without difficulty, then try a quart and see if you can manage that.
As you become more comfortable with taking enemas, you may find that eventually you are able to take a full 2 quart bag without unpleasant discomfort.