Honestly even more, just . . . IV fluids.
The fact that we can put fluids into people via IV saves more lives than I can actually communicate. There are so, so many more ways to die when we can't do that. You can go from literally at death's door from an illness you have no other cure for, to Basically Fine, You'll Feel Icky A Bit Longer But You're Otherwise Fine and Your Own Immune System Will Work Now, from sterile saline into a vein.
Or even fucking subcutaneous, under your skin. It still gets into your system faster and bypasses any fuckery going on in your gi-tract.
But you want the other end?
I recently got the answer to a crapload of symptoms of mine and it turned out to be Crohn's. Ileal crohn's.
For most of human history there was literally nothing to do about this but hope and pray that your immune system didn't decide to rip ulcers and lesions in your digestive tract to the point where you bled out, or the point where parts of it died and killed you with sepsis, or enough to build up stricture bands of scar tissue sufficiently to cause impactions or any other really gnarly and unpleasant ways you can die because for some reason your body decides the walls of your digestive tract are the enemy and need to be dismantled cell by cell. (Including a fuckload of cancers caused by the constant damage to the cell wall.)
Even as recently as when most of the younger people reading this were small children, mostly all you could do about it was take corticosteroids when you were in a flare. And that was better than Nothing. But at the same time, corticosteroids have a potential laundry list of side effects and you want to take them as little as possible and for as brief a period as possible. And there wasn't a lot else.
I am on a medication with the proprietary name "Skyrizi" and the generic name risankizumab. It's made from taking antibodies from a non-human source and then modifying their protein sequences to be more similar to human antibodies, after which they modify them further in order to make it so that the literal only thing they do is go into my body and bind to something called "tumour necrosis factor" so that this will stop flagging my own goddamn digestive system walls for destruction by the rest of the immune system.
Please feel free to read that paragraph over again.
Modern medicine isn't perfect; there are many things we're just as helpless against as we were in the Days of Eld, and there are many ways its practitioners fail us. But also we can make a thing that goes into my body and says "hey stop self destructing you MORON!" and I have a much better chance than at any other time of not dying young of bowel cancer or bowl impaction! This is fucking insane.