Hospitals were reluctant to give enemas for a few reasons, IMO.
For starters, it takes at least 15 minutes to get a large volume enema kit from the supply room, run warm water and prepare and fill the bag for use, protect the bed, give the enema, This far longer than giving a Fleet or suppositories or pills.
Then, when the enema works, the patient poos strongly and in a hurry. if the patient can use the toilet, there is always the chance the enema will work, uncontrollably, before the patient can get from the bed to the toilet, or worse, fall and injure themselves. The same applies to a bedside commode.
If a patient uses a bedpan after a bag enema, a sloppy mess is almost certain. Neither a slipper (fracture) nor a standard bedpan can hold 1500ml of solution unless it's perfectly level, A lot of poo makes the situation worse. And it's hard to keep the bedpan level, both as the patient poos, and especially during removal and transporting the filled bedpan to the toilet to be emptied.
Some of the older bedpans, like the Jones Relax, can hold more liquid than the current plastic ones, but they are very uncomfortable to use, even in a hospital bed that can have the head raised.
Frankly, from person experience, the easiest and most comfortable way to expel a large volume enema in hospital is with the patient lying on their left side, on several Chux pads. A pad is folded over the patient's buttocks to contain any solution sprayed out. I once received a Lactulose enema of 1500ml this way and the results were very effective, but cleanup is a mess. I've read that this was the preferred way to give a pregnant woman a pre-drelivery HHH enema, years ago.
Finally, many people are adverse or very adverse to having a large volume enema. They would rather lie in bed, uncomfortable and rectum packed with poo for hours until pills make them poo, than be embarrassed by completely losing bowel control after an enema.
As to hospital food, I've found to be actually pretty good.... not 5-star eatery quality, but certainly better than most all fast food places. It tends to be fairly bland and low salt.