So the thing is no "swim diaper" for babies or adults is made for urinary incon their main goal is to prevent fecal matter. Urine is technically sterile and most pool use enough clorine. Some do offer light protection but that is about it. Usually every summer a new parent will post a video or reviews somewhere because they left their new child in like Huggies little swimmers and they pee everywhere.
This is an issue I struggle with because even though I am dual ic most of bowel ic happens at night. But it makes it really hard because if you plan to swim you need to change in my case put on a swim diaper as I would hate to be that person swim get out right away get rediapered. It makes going to pool or water events hard but it's also one of those days I will use either cloth diapers or a cloth backed diaper I find being hook n loop fasteners if I didn't use it I can put it back on after I get out and if I want to swim again I am not wasting more expensive diapers same with cloth diapers sometimes if I go to something once I get out of I plan to swim again soon I will put on a day weight cloth diapers and like use like cloth backed.
Two solutions or sort of so the swim diapers that I use most often one is by a company Sosecure other I forget but both washable both are fleece lined so normally I will put a cloth prefold in it which can help prior to.getting in, but once in the water it will get wet but does offer some protection(if I am 100% I didn't have bowel ic I will pull the leg band as I am getting out so the water to let excess water out). The other is think Rearz sells them is their latex rubber pants , for me being paralyzed there hard to get on but being actual rubber pants they create a tight seal around legs and waist I have worn them safely over disposable diapers and had no issues but because their rubber I have had some break as I was putting them on so it's like a $20-30 gamble. There is a YouTube channel called K Huck and he has similar results as i did. But you need to make sure they create a good seal or they won't work. If traveling I will bring Tranquility Swimmates which are disposable pullup swim diapers they will handle small voids but not guaranteed.
But whatever you do don't wear a regular diaper into a pool not only does it become an achor which can be a safety risk but if the diaper breaks or explodes the sap can screw up the filters or that what they say and like wearing swim diapers I rather not be that guy.
