My 93-year-old wife constantly commutes between two bathrooms. What's up with that?

ThisThis is a very common dementia-related Behavior. It often seems very confusing to caregivers and other family members. It is called seeking. This partially occurs I think due to the bursts of energy without the connection to specific tasks that somebody with dementia May encounter. Kind of like if they stare out the window mouth open kind of like a zombie and you wonder what they're looking at. They're often not looking at anything. They might be remembering something and thinking they're actually seeing that. It has to do with their brain and the way it's processing versus prior to dementia. Before dementia your brain is evaluating your system for what you need. Things like going to use the restroom, going to the kitchen to fix food, going to the front door to answer it, going to the mailbox to get the mail.. when your brain forgets to tell you where to go and why to do it sometimes you end up on a sort of autopilot, in seek mode. This is what I've gathered from the doctors about my mother's own seeking habits which do include between 4
and 8 trips to the restroom each hour she's awake..

My 89 yr old mom spends a lot of time urinating. A constant urge to go. She is 90 ish. No utis. She has incontinence and hates being wet. It is overactive bladder. It keeps her busy. I ignore it.

You seem to have ruled out anything I can think of, so I am just going to have to say it just is what it is. There isn't a lot of rational thinking you can do about an irrational mind. If she seems contented, and she is--as you say--getting some exercise, I don't know I would worry overmuch about it

OCD behaviors run rampant with dementia, such actions go with the territory. Repetitive acts of all kinds are typical, especially where toileting is concerned, for some reason. My mother was obsessed with the toilet during her heyday with dementia and there was no distracting her from her mission.

I suggest you read this 33 of booklet online about managing dementia and what to expect with an elder who's been diagnosed with it.

Understanding the Dementia Experience, by Jennifer Ghent-Fuller 
https://www.smashwords.com/books/view/210580

Jennifer is a nurse who worked for many years as an educator and counsellor for people with dementia and their families, as well as others in caring roles. She addresses the emotional and grief issues in the contexts in which they arise for families living with dementia. The reviews for her books are phenomenal b/c they are written in plain English & very easy to read/understand. Her writings have been VERY helpful for me.

The full copy of her book is available here:

https://www.amazon.com/Thoughtful-Dementia-Care-Understanding-Experience/dp/B09WN439CC/ref=sr_1_2?crid=2E7WWE9X5UFXR&keywords=jennifer+ghent+fuller+books&qid=1657468364&sprefix=jennifer+ghent%2Caps%2C631&sr=8-2

As her condition progressively declines, you need to look into hiring in home care or placing her in Memory Care Assisted Living. Oftentimes, dementia and AD behaviors become too intense to deal with alone at home. Don't become a statistic where you die from stress before she does! Recognize you need help and hire some.

Good luck.

Thank god that she can go by herself. We have two commodes in the house. One is in the bedroom and the other is in the living room. My wife will not go to our bathrooms. Don't worry about her choices and be grateful that she is moving.

Don’t even try to make sense of what/why dementia patients do or say. The mind is an amazing, complex thing. It’s like trying to make sense of a crazy dream…things don’t make sense, snippets of seemingly unrelated things, people and places are not what they seem etc.

As long as she’s able to get around and to use the toilet properly, be thankful and try not to over think it or correct her. It won’t be worth it.

Is she incontinent?
It is possible that she just wants to make sure that she does not have to "go". And when she does go is she able to empty her bladder completely? It is possible that there is still a bit of an urge to go.
And how often are the trips to the bathroom?
If it is every 2 hours or so I would not worry about it at all.
If it is every 15 minutes I would suspect that this is just a "dementia quirk". My Husband would get obsessed about shaving and he was in the bathroom shaving 4 or 5 times a day. And that was after his shave, shower in the morning.
He did the same thing with brushing his teeth for a while.
As with a lot of things someone with dementia does...that phase passed and he would pick up another "quirk"

The bathroom is an important part of daily life and she may be obsessing about getting there or being there. At.least she CAN get there! Better than not being able to get to the bathroom when needed. Don't worry about it.

Dementia is weird. It's crazyfying. Don't try to make sense out of nonsense. Just be glad that she's walking, because she might not be walking for much longer.

lepleydm: Your wife has developed a habit, which is a compulsion to travel back and forth to each bathroom. Compulsions are quite common with this disease. As she has dementia, you won't be able to easily break the habit. Be grateful that she has zero toileting issues. You can garner information on the disease by reading the book, 'The 36 Hour Day.'