@trust If you like feeling full and belly distension large enemas can definitely deliver that. However, I suggest beginning with smaller quantities like 2qts and then gradually moving up.
As well, unless you like cramps, do not use plain water or any irritating additives like soap, baby shampoo and so on. Only salt. Salt will prevent water absorption and cramps.
Another important factor is water temperature, the colder it is, the bigger cramps. But do not use too hot, as it can cause serious damage! 100-103F works the best for me.
And finally, speed of delivery, the faster it flows, the bigger cramps, so hung bag low and take breaks.
As for problems with expelling, I am afraid this is given when using larger volumes. Just do not try to force things, take breaks, stand up, walk around. Patience and being relaxed is the key. It can take even over 20min for last 'trapped' water to come out.