I know it's weird to ask. But I've always wondered. How did characters in fantasy...poop? How did they handle their bowels? I mean, maybe the ones capable of magic would make it to where they simply don't need to, and by extension not need to eat either. But what about the ones that aren't capable of that sort of magic? There aren't any porta potties, or any bathrooms seen in any fantasy books. So how did they go? Just ask their magical friend? Are all fantasy characters chronically constipated? What if the magic friend is not there? "Hey, wizard friend. I need to go." Wizard friend snaps his fingers and the shit inside the guy is magically gone. "Thanks." Is it like that?
We aren't shown chamber pots and latrines because they aren't relevant to the stories. It's similar to how fantasy novels never have scenes with characters grooming their toenails.
The most basic way is to dig a hole, drop trou, take care of business, and then bury your feces for the good of the species. Large trenches intended to accommodate lots of people pissing and shitting at once are called latrines. If you've ever been in the Army you might have had to dig one yourself. Towns and villages often had outhouses, and castles had privies. For the most part you don't hear about people pissing and shitting in fantasy novels unless something plot-relevant happens. For example, suppose Aragorn son of Arathorn is taking a dump at the Prancing Pony. Nobody cares, because it doesn't add anything to the story. Now, suppose a Nazgul walks into the crapper while Aragorn is there and demands that Aragorn not help Frodo. Now things are getting interesting.
This is a history question, not a fantasy question. Historical novels also rarely discuss these issues, because they’re rarely plot-relevant. I do have a period where Character A is fairly seriously injured and stuck indoors for some time. I did throw in a moment of Character C being surprised that Character B, who cared for her for a few days, apparently carried out her waste and cleaned sufficiently that the sickroom had no associated smell, because C had never imagined B doing that kind of work. And there was mention of a waste bucket in a prisoner’s cell. But without confinement, I think these things are just ignored.
As others said, unless it ties in with the plot (ie--someone putting a deadly spider in a chamber pot), probably not worth mentioning. That said, it's never been a burning question on my end as a reader.
They don't? Well, darn. *Goes to WIP and deletes several scenes* Lol, jk. It's what people have already said- if it's not directly relevant to the story, who cares? Your readers will assume that your characters take care of business as usual.
I do think that it’s something to keep in mind when characters are for some reason indoors or in confined spaces for an extended period of time. We’re accustomed to water in and sewage out being not-an-issue; for plausibility it might need a sentence or so. “No, you can’t have four stonemasons. I need every ablebodied man on guard duty.” “This castle hasn’t been occupied in twelve years. The privy drain is full of trees and overflowing toward the well.” “(Expletive). Take three.”
Well, I'm going to buck the trend here and say yes, it does matter. To some extent, anyway. Because it's a bodily function that more or less every creature on earth actually does, it would be nice to have some notion of how waste is handled in the world of the story. It doesn't need to be a main part of the story, but still. There will be times, no doubt, when it will be relevant. Although it's not fantasy, I remember reading the Laura Ingalls Wilder series of books (popularly known as the Little House Books) as a child, and certainly wondering where in heck they went to the toilet. There were many instances where the family was confined to quarters for various reasons, including blizzards, etc. So ...where did they 'go?' As a child, I always wondered. I was familiar with outhouses, because many cottages and camps that I visited had them and did not have indoor plumbing. But they were, of necessity, located some distance from the cottage or camp and involved a bit of a trek to do the business. So the fact that Laura and her family were cooped up in a house or shanty for days or even weeks on end, not daring to set a foot outdoors because of either the cold or getting lost in a blinding snowstorm, did make me wonder. The facility was NEVER mentioned in any of the books, yet must have played a pretty important role in the life of the family. The Long Winter must have been long indeed, if they never got to poop or pee for months on end! They probably also had chamber pots of some kind, but again these were never mentioned—nor where or how they would have been emptied. The Lord of the Rings didn't bother me because so much of it took place in an outdoor trek, and you just assumed they were using the great outdoors, as needed. And the indoor locations (The Shire, Rivendell, Gondor, etc) must have had 'facilities,' as they were where lots of people lived. It's when the plot ignores the need for toilet facilities and disposal altogether, but puts the characters in a situation where they would definitely have had a problem with mounting 'sewage' and it never gets mentioned, that I begin to doubt the story a bit. Basically, any household or collection of people has waste to dispose of. Either they do it efficiently, or they don't. Either way, I think it deserves a mention. Especially if it's obvious they are not going to have a good way to dispose of it. Any buildup will impact on the lives of the characters, to a rather huge extent. Pretending it doesn't exist doesn't make it go away. I think this issue needs to be built into any worldbuilding exercise, just like eating and sleeping will be.
There's a book called How NOT to Write a Novel and it says that the reader, "also knows that everybody poos, but make your character poo in front of the reader and they'll be known as the pooing character forevermore". Barring perhaps treants, since they're sentient plants, if it's humanoid it is likely presumed they have a similarly functioning excretion system. Diet may affect what comes out though.
In The Bible the "How To Poop" section is at Deuteronomy 23:12,13. Probably not the type of fantasy you were looking for, though.
Although, I can very easily imagine a wizard contemplating the arcane mysteries of the cosmos whilst he dropped a steaming obsidian brick. (I'm sorry for the crudeness, but I couldn't resist).
It's the same as when people go camping in the wild or trekking through the Appalachian trails. BTW, characters do poop in S.King's Dark Tower series, which is fantasy. It's not essential to the story but the author has found an interesting way of describing it and it's there. If you don't find an interesting way of describing it, it doesn't have to be there. At least people who camp and trek will know how it's done . For the rest there is always a forum on the internet where they could ask. PS. I totally liked your invention with the magic way of dealing with it