My mom who is 83 might be coming to live with me. Since being in a rehab facility, she’s been wetting the bed almost every night. Advice?

If your mom has funds for care then you should rethink your decision to be her carer. It’s a monumental uphill task and needs just become greater. Better to have her live in a caring facility and you keep your sanity than have to move her later when needs are too great and you are burnt out.

Uh, I'd rethink the entire 'living with you' situation right away. Or get used to the house reeking of urine along with the carpets and everything else she comes in contact with. Is it absolutely imperative that she live with you? What about Assisted Living??

Anyway, for the urine soaked garments, use a vinegar wash:

Mix one cup white vinegar to three cups water (1:3). Coat the urine-stained item with this solution and allow to sit for a few minutes.
Cover the stained area with baking soda, if you wish. ...
Wash the urine stained items in a washing machine set on cold or lukewarm water. ...
Air-dry the urine-stained items.

For the bed, purchase a plastic mattress cover and Medline Extrasorb chuck pads on Amazon.

https://www.amazon.com/Medline-Extrasorbs-Drypad-Underpads-Permeable/dp/B07GYZNDY8/ref=sr_1_1_sspa?crid=60PNIEXGYCJ6&keywords=medline+extrasorbs+ap+30x36&qid=1582245028&sprefix=xtrasorbs%2Caps%2C1615&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzVTdVSlhHQU1NUUlIJmVuY3J5cHRlZElkPUEwNzc1OTI4MVM1WTNSSlU1V0xHMiZlbmNyeXB0ZWRBZElkPUEwNDY3MTgzMlhNU0lXQUI0RFdRNyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

She will need to wear Depends to go to sleep and you can also buy doubler pads to insert into the brief to soak up extra urine.

Good luck

If she is definitely coming to live with you, do this-
Remove carpet from her room and replace with LVP.
NO THROW RUGS
Get her a lift chair that is vinyl upholstered.
Hospital bed and bedside commode.
Hoyer lift
Use a waterproof mattress cover, then a chuck pad and then fitted sheet on top of that. Buy plenty of sheets.
She needs to be wearing adult diapers.
I'd have her spending most of her time in her room if she is peeing everywhere or else your house and furniture are going to end up smelling like urine.
Prevent, not mitigate

Borax powder for clothes, I just posted that on another question. I found that tip here on the forum and it works! I had tried everything and borax was the only thing that worked. The instructions were to add 1/2 cup to the laundry with your detergent but I always used at least a full cup. Try it, it really does work.

Make sure the bed she’ll be sleeping on has a waterproof sheet under the regular sheet. Buy several good ones so you can swap them out when wash the bedding.

You can buy room air cleaners, machines with filters that help. You can also buy charcoal pouches that you can toss under her bed or anywhere she might have an accident. If she wears adult diapers, buy good ones and make sure they fit properly. Don’t let her sit on anything that isn’t completely covered in plastic first.

Is she mobile and can she toilet herself during the day? Make sure you understand the extent of her needs before you undertake her care. I cared for both of my folks for several years before they died and their deaths were nothing but a huge relief for me. As much as I loved them, I’ve never grieved a day for them. Caring for an elderly parent can and will suck the life out of you, no matter how much you love them.

Either you are unusually sensitive to the odour of urine, or you are not washing the laundry at a high enough temperature, or there is something wrong with your mother's urine.

Urine from a healthy urinary tract is not especially smelly, or not until it's been left lying around the place for a while anyway; and a biological detergent + a good hot laundry cycle + in-wash disinfectant should leave bedlinen perfectly fresh.

What do you think of the care your mother has received so far at this rehab facility? If they can't even keep her dry and comfortable at night it doesn't sound promising...

I see you say she might be coming to live with you. If she is not safe to live alone, if there are any other options, that would be better. Just because she is your mother, does not mean her care has to become your job. Urine may be be the only thing she cannot manage on her own. And the whole process of managing all that and whatever else she needs would be very intense.

So, plenty of suggestions here - disp briefs, waterproof mattress + bed pads, etc., plus laundry options (do heed my warnings about vinegar and bleach - big NONO!) Your profile indicates this plan to take mom in is temporary, but you also mention that her "mental and cognitive have declined.", so this plan may have to change. It all depends on finding out what is behind the night time bed wetting. Taking care of the issue and laundry is secondary - this should be the more important aspect.

While this is of concern (no idea why she's in hospital rehab, was it injury or stroke?) and should be checked, note there are other, often treatable, medical issues that can contribute to both the cognitive decline and bed wetting. If she had a stroke, it may be why her cognitive abilities have declined. If she had any anesthesia, it can also contribute to cognitive issues. Sometimes these can resolve over time (being in unfamiliar places, esp moving to hospital then rehab can also contribute to some confusion), but she should have a full checkup when she is ready to come "home" or as soon as possible after discharge, whether it is to your place or hers. She may not be able to pass the mini-mental exam, BUT it would be a baseline, so if her condition improves, it would be observable.

I did see someone finally mentioned the UTI. Your profile indicates she has had some issue with UTIs. When I first joined this forum, I was skeptical of the UTI comments, until it happened to my mother! She used to have UTIs several times/year when she was still competent, and would manage to get it checked/treated on her own. Many months after we moved her to MC, she got her first UTI there and had severe sun-downing (agitated, demanded she had to get out, go home, had guests, etc) This went on every day later in the day until the UTI was found and treated (it started on a Fri night, so no access to doc! Also, she would be "fine" in the morning!) We also had to add anti-anxiety until it was resolved.

So, your mother isn't having sun-downing, BUT, I wanted to mention the above because it IS a sign of UTI. Too often in elders there are no "typical" signs of UTI. That said, the next 2 UTIs mom had resulted in night time bed wetting - SOAKING everything! No sun-downing, just soaking the bed, herself, etc, even with disp briefs. Once it was found she had a UTI and it was treated, the bed wetting stopped. The nurse in charge realized this when the second episode of bed wetting happened, so it was found and treated sooner!

So, one component of that health check before she comes home or as soon as possible after is get her checked for UTI - the dip stick test may not be enough, you should request a urine culture, esp since she has a history of UTIs. It might be wise to see if this can be done NOW, before the planned discharge.

Meanwhile, you could start learning about dementia, researching what's available for services (hired aides for her home or yours) and facilities, because if this is dementia, eventually you ARE going to need help and/or find a place for mom. Being a working single mom is hard enough (been there, done that!), but if mom's care is going to be more than just providing a safe place temporarily, you are most likely to get in over your head!

You can purchase waterproof pads for the bed. I would buy a waterproof mattress pad, then medical companies supply waterproof incontinence pads that are small and easy to wash. They sell them on amazon. In addition, absorbent diapers for bedtime provides additional protection.

I had the same issue before I read on the forum about white vinegar. I add white vinegar to the warm wash cycle using the bleach dispenser and everything comes out smelling fine - clothes, bedding, and washable pads. I also include white vinegar in the carpet cleaning solution and the bathroom mop water. You can smell the vinegar for a while during cleaning, but it dissipates leaving the normal cleaning solution smells.

Mom wets bed every night. I have found a few things work.
1. Get and start washing the wet things AS SOON AS SHE GETS UP. Mom gives me a bad time about getting the nightie, but time = smell.
2. I rinse soiled items with a cup of white vinegar (buy the store brand in big jug) then wash in warm water with Tide. Others have favorite detergents but Tide works for me.
3. Whenever possible, I put sheets, bed pads, nighties, etc. outside to dry. Sunshine is a natural disinfectant and leaves smelling good. I run those items in dryer on "fluff" cycle with dryer balls to soften.
Sounds like a lot of work. It is, but you develop a routine.

GOOD luck and if you learn something, pass it on.