Why aren’t enemas recommended more for constipation?

I’m 15 weeks 6 days, and I’ve had my fair share of struggles with constipation during this pregnancy. I drink plenty of water, stay physically active, and eat fibrous foods.

The first recommendations I received were Metamucil and MiraLax. Those did not help. It was alarming to drink MiraLax 3 days straight with no bowel movement. After finally a week with no relief, my husband did some research and recommended a saline enema (Fleet). The product seemed too good to be true - relief and a bowel movement within 1-5 minutes? But sure enough, it delivered. So far this is the only guaranteed quick solution I’ve discovered. Prune juice also ain’t cutting it for me.

So my question is, if saline enemas are safe and so good at what they do, why aren’t they recommended more? Why did I have to buy 6 products and prolong my discomfort before relying on them as a last-ditch effort?