The Truth about Swim Diapers and Exclusively Breastfed Babies

*WARNING: This may be a little TMI for some! 

Got a baby? Planning on spending some time by the pool? You’re gonna need a good swim diaper. The purpose of all swim diapers is not to absorb, but to hold in solids. “Solids” is a nice way of saying poop. :) But what if your baby’s poop is not so solid?? What if your baby is exclusively breastfed? That’s where things get a little tricky…

baby in swimmi

This time last year, I had a growing, thriving 10 month old. Since we were practicing baby led feeding, he was still mainly breastfed at that point. I encouraged him to eat with us whenever we would sit down for meals, but he just wasn't interested at the time. Like most exclusively breastfed babies (meaning their diet consists only of breast milk) his stools were still pretty runny. This is great for diaper laundry! Breast milk poo is water soluable, meaning it dissolves easily in water. Because of this, there is no need to get rid of the poo before putting it in the diaper pail. It should easily wash out and come clean in the washer! This, however, is bad news when it comes to swim diapers.

Swim diapers aren't made to be absorbent. If they were, they would immediately start absorbing the water the baby is swimming in and swell up! So when baby pees, whether they are wearing a disposable or a reusable swim diaper, the pee goes right out the side of the diaper. This is why public pools are so heavily chlorinated. We all know people are going to pee in the pool. Babies pee in the pool... kids pee in the pool... ADULTS pee in the pool. It happens. What a swim diaper is designed to do is catch solid waste and keep it from contaminating the water.

Last year, I wasn't even thinking about this when I decided to review a swim diaper on my blog, Apron Strings Attached. I was really impressed with it, but I knew before I could finish my review, I needed to put it to the ultimate test... I need to see if it could contain the poo. Problem was, whenever my son was in the water, he never went! I came up with a plan... Since he was pretty regular, I put the swim diaper on him at a time that I knew he would be “going” soon. I waited and waited and when I knew that he had went, I put him in the baby pool and let him splash around. After a few minutes, I lifted him out of the water… total fail...  as evidenced by the yellow trickle running down his leg. :(

baby getting in pool

I wondered if maybe I had bought the wrong size, but it looked like a great fit, and when I checked around the waist and legs, the elastic was nice and snug. I decided to reach out to the manufacturer to see if this was just the reality of breast milk poop, and they agreed. Swim diapers are intended to hold solid waste, and anything liquid will pass through.

I decided to see how disposable swim diapers would compare to reusable at containing EBF poo. Just like I did with the reusable swim diaper, I put it through the ulitmated test of the baby pool, and it proved to be even worse! The elastic around the legs and especially around the waist couldn't compare to that of the reusable swim diaper. 

 That didn't stop us though from enjoying the pool or any body of water for that matter! We found a combo that worked great for us while my son was exclusively breastfed. When we were going to be using a public pool, we paired our two favorite reusable swim diapers together to get double the protection. I used our AppleCheeks (which is my absolute favorite swim diaper, but does NOT have a waterproof layer) underneath our Bummis Swimmi (which I love as well, and DOES have a waterproof layer). At home, we just used one or the other and watched him closely for signs that he needed to go, so we could quickly take him out of the water (although he's never actually went while in the water).

baby by lake

If you're looking for a swim diaper to use at a public pool and your child is exclusively breastfed, I would recommend a diaper that is VERY snug around the legs and has PUL or TPU (a plastic-like layer bonded to the fabric to make it waterproof). Check the pools rules. Many pools require a swim diaper covered by plastic pants. I considered my AppleCheeks to be my swim diaper and the Bummis Swimmi over top to be our plastic pants. 

Once your little one starts taking solids, the stools should start to bulk up and it shouldn't be as much of an issue. Until then, just keep and eye out for signals that he or she has to go so you can quickly get them out of the water. Of course, if you're playing in the water in your own backyard, you don't have to worry about being banned for a code brown! ;)   

*Although I am compensated for my time spent writing this post, all opinions are my own and cannot be bought!

About the Author: Stephanie Beck is a blogger and Social Media Coordinator for The Green Nursery. She is a busy mama of four who enjoys being outdoors, cheering on her kids' sports teams, and spending time with her family. She loves photography and has recently started up a new blog to share her photos and journey as a budding photographer. You can find her at


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