A deep dive on bidets

From time to time on this blog, I've talked about the idea of getting a bidet to reduce or eliminate our toilet paper use. Every time, I've concluded that it wouldn't be worth it. We spend so little on toilet paper that it couldn't possibly save us that much money, and since we use the recycled stuff, it wouldn't save trees either. So I decided the benefits of a bidet wouldn't outweigh the costs, and that was the end of it.

Except the Internet doesn't want to let that be the end of it. Since the start of the pandemic and the ensuing TP shortages, I keep seeing articles everywhere—from the Washington Post's Climate Coach, from the New York Times' Wirecutter, from Consumer Reports—singing the praises of bidets. And it seems like virtually every thread on Reddit about either sustainability or frugality (or, really, almost anything) eventually gets hijacked by bidet fanatics going on and on about how this little device has changed their lives and implying that mine will never be complete without one. It's like some kind of weird plumbing cult.

So I decided I needed to look into this issue in more depth. Am I truly missing out, and/or harming the planet, by stubbornly sticking to my Trader Joe's TP? Or is it the pro-bidet claims that don't, so to speak, hold water?

The pro-bidet crowd makes four main arguments in their favor, which I'll tackle one by one:

1. The financial argument

Many bidet fanciers claim that a bidet will pay for itself in months or even weeks because of all the money it saves you on toilet paper. To back up this assertion, they offer a wide range of statistics about the "average" American's toilet paper use, ranging from 3 rolls per week to 2 rolls per day. (How is that even possible?) The figure I'm most inclined to trust comes from Statista: 141 rolls per person per year. (This is based on a weight of 90 grams per roll; I just weighed one of ours and it's actually a bit smaller, at 80 grams.)

While this may indeed be accurate as an average, it's certainly not true for us. Last time I tracked our toilet paper use, I found that our family of two goes through roughly 68.5 rolls per year, just over 34 per person. Admittedly, I did this experiment at a time when Brian was working at the office five days a week rather than one or two. But according to Brian, even then, nearly all of his toilet paper use occurred at home. So even if he used, say, a dozen sheets per week at work, that only works out to around two and a half rolls per year. That means our TP usage now comes out to roughly 71 rolls per year.

The toilet paper we buy at Trader Joe's has also gone up a bit in price since the time of my experiment, from $4.50 per dozen to $4.99. But at 71 rolls per year, that still puts our annual TP cost at only around $29.50. According to Consumer Reports, the cheapest available bidet attachments cost around $30, so there's literally no way one could pay for itself in less than a year. And Wirecutter's top-rated bidet seat, the $400 Toto Washlet, would take over 13 years to pay for itself—assuming it lasted that long.

That's also assuming that a bidet would eliminate our use of toilet paper entirely. However, it's by no means clear that it would. There's widespread disagreement online about whether a bidet is a replacement for paper or merely a supplement to it. Some folks say they use the bidet first to wash, followed by toilet paper to dry off; others say they wipe first, then use the bidet to get fully clean. Several bidet users interviewed by Consumer Reports said they used less toilet paper since getting it; one said it had cut their family's TP use by about half, while others said they use "up to 80 percent less." If our experience was the same, a bidet would only save us between $15 and $24 per year and would take 1.3 to two years, minimum, to pay for itself.

Except there's one more problem: A bidet would add to our household's annual water use. Each use consumes about two cups of water. If we both used it every time we sat on the toilet, that would be, according to my rough calculations, about 24 cups (1.5 gallons) of water per day. (I'm estimating that we each use it twice a day for a bowel movement and I use it an additional eight times a day to urinate. If we used the bidet for bowel movements only, it would consume only about half a gallon of water per day, but it would also eliminate no more than one-third of our toilet paper use.) 

We don't pay for our household water by the gallon; our town uses a tiered system, and our quarterly water usage is generally low enough to put us into the lowest tier, up to 799 cubic feet. But not by much. Particularly in the summertime, we often get up into the 700s and occasionally even top the 800 mark, bumping us up to the next tier and costing us an extra $23.44. If we were using a bidet regularly, that extra 1.5 gallons per day would make it that much trickier to stay in the bottom tier. If it bumped us up into a higher tier even once per year, that would erase all or most of our TP savings.

In the absolute best-case scenario—we acquire a bidet for no more than $30, it saves us $24 a year on toilet paper, and it never bumps our water bill—it would pay for itself in 15 months. But it hardly seems like it would be worth the hassle for such a small savings. Which brings us to...

2. The environmental argument

The main reason "you need a bidet," according to the Climate Coach, is "to reduce clear-cutting mature forests." Millions of trees, the article claims, go to satisfy American's gluttonous need for toilet paper and our pigheaded refusal to switch to bidets. But once again, this doesn't really apply to us, since our TJ's TP is made from 100 percent recycled paper, with a minimum of 80 percent post-consumer recycled content. (N.b: that means it's made from other kinds of paper, not toilet paper that's been recycled post-flush.) 

Now, tree pulp isn't the only resource that goes into making toilet paper. Treehugger argues that the best reason to use a bidet is because, ironically, they save water. "Paper making is incredibly water-intensive," the article claims, and the wastewater from the process creates "a flood of organic waste and chemical residue which must be processed or, worse yet absorbed, after being treated and dumped into some unlucky river or ocean."

But here, again, it's not clear that the math works out in favor of bidets. According to the Climate Coach, each roll of toilet paper requires about 6 gallons of water to produce. We take about 5 days to go through a roll of toilet paper, so that's 1.2 gallons per day. And according to my off-the-cuff calculations, switching to a bidet instead would use up 1.5 gallons per day—0.3 gallons more than just using paper.

In fact, it's probably even worse than that. When I clicked through to the Climate Coach's source for the 6-gallons-per-roll figure, an episode of the Possibly podcast, it said that "A roll made from 100% recycled materials uses half as much water." Thus, cleaning our butts with recycled TP uses only 0.6 gallons of water per day—less than half as much a bidet. In short, if the main purpose of using a bidet is to save water and trees, it looks like our recycled-fiber TP actually does significantly better.

[UPDATE, 2/15/24: I've since found some more reliable numbers on water use. A little further digging led me to the Environmental Paper Network's Paper Calculator, which you can use to calculate the environmental impact of various kinds of paper use. I punched in the weight of a 12-pack of our Trader Joe's TP (about 2.1 pounds) and selected "tissue" for the grade. It said this amount of paper would use 42.8 gallons of water—3.56 gallons per roll—if it contained no recycled paper content whatsoever (either pre- or post-consumer). If made with 100% recycled paper content, it would use only 22.5 gallons, or 1.875 gallons per roll. Thus, the amount of TP we go through in one day uses only 0.375 gallons to produce—one-quarter of the amount we'd use with a bidet. Thanks to the Handy Finch blog for helping me find this source.

Obligatory citation: Environmental impact estimates were made using the Environmental Paper Network Paper Calculator Version 4.0. For more information visit www.papercalculator.org.]

3. The hygiene argument

A lot of bidet users argue that it's simply not possible to clean your bum adequately with toilet paper alone. One analogy they're fond of using is, "If you got poop on your hand, would you just wipe it off with paper? No, of course not! You'd wash it off with water!"

My inclination is to respond to this with a snarky, "Well, that's because I pick things up with my hands, and I almost never pick anything up with my butt." But in the interests of fairness, I thought it was only right to look into this argument as well. Is a bidet really superior for cleaning?

Amazingly enough, it appears there are few to no scientific studies addressing this question. But as a colorectal surgeon interviewed by Smithsonian magazine points out, "It kind of doesn’t matter." Failing to get every last particle of poop off your bum will not in any way harm your health. There's some evidence that switching to a bidet may offer some relief for people who suffer from pruritus ani (itchy butthole) caused by over-wiping, but there's also evidence that "excessive" bidet use may cause this problem. Another expert interviewed by Smithsonian says a bidet may be helpful for people with specific disorders, such as Crohn's disease or physical disabilities that make wiping difficult, but those problems don't apply to us. In fact, for me, at least, a bidet would more likely do harm than good. Regularly using the "feminine wash" setting on a bidet to clean the lady parts can spread fecal bacteria to the vagina, which definitely isn't desirable. 

[UPDATE, 1/31/24: In the interest of fairness, I should add that a recent "Ask a Doctor" column in the Washington Post cited a 2022 study showing that bidet use doesn't just clean your butt better; it also greatly reduces the amount of bacteria on your hands after you wipe. A small sample group, 32 nursing students, wore clean gloves while using the toilet, and afterward the gloves were tested for microbe contamination. Result: the gloves of the TP users had nearly 10 times as many microbial colonies as the gloves of the bidet users. But here's the catch: as far as I can tell from the abstract, the volunteers did not wash their hands after wiping and before handing over the gloves to be tested. And in the real world, based on my observations in public restrooms, the overwhelming majority of people do wash their hands afterward, even if they don't always do it for the recommended 20 seconds. So I don't think this study provides much useful information about how clean the hands of TP users and bidet users are in real life.]

4. The hedonistic argument

In short, there's no sound reason for using a bidet to promote better health. But for most users, having a squeaky-clean bum isn't mainly about health; it's about happiness. Over and over, I see bidet lovers using phrases like "Once you've tried it, you'll never be able to go back to just paper" or "once you have one you feel like an animal not having it." (That latter one, by the way, was a response to a complaint about how annoying bidet evangelists are.) Some even say they can no longer stand to take a dump anywhere except at home.

Since I've never experienced this myself, it's not an argument I can refute. Maybe a sparkling clean butthole really is one of life's greatest pleasures, and I can't possibly say it isn't worth it without having tried it. But the same could be said about heroin, and I've never found that a compelling reason for trying it. Because the worst-case scenario wouldn't be that I didn't like it; it would be that I liked it so much I couldn't live without it.

This, for me, is the best argument against getting a bidet. I don't want to be a person who can't use a public restroom (or who needs to carry a portable bidet everywhere she goes) because she can't bear to clean up with paper. And even more than that, I don't want to become a person who is so enthralled with her bidet that she can't stop talking about it. I don't want to drive my friends, my family, and complete strangers on Reddit up the wall by telling them constantly why they need a bidet, and they may think they don't, but that's just because they haven't tried it, and once they do they won't know how they lived without it, and anyway it will pay for itself in a month and save the forests, and there's no way to get truly clean with just paper, and how can they stand to walk around with a dirty anus?

If I had found that a bidet truly had significant benefits for my health, my wallet, or the environment, I suppose I would have to bite the bullet and get one, even at risk of turning into an annoying bidet snob. But fortunately for me, none of these things appears to be the case. I'm not telling anyone who has a bidet and loves it that they should stop using it; I'm just saying I see no good reason to get one for myself, and I'd appreciate it if we could talk about something else.