Is it a given that all patients with dementia will have incontinence at the last stage?

My mother, who had vascular dementia, never was technically incontinent. Not even up to the last few weeks of her life when she became totally bedridden. She still had the urge and wanted to get up and go to the bathroom. Unfortunately, we had to convince her she didn't have to get up and could go right where she was, which was not easy for her to do.

In my experience, and the reason I think it becomes the rabbit hole that is so frustrating/confusing for caregivers, is that it goes beyond what we normally think of incontinence. Rather than just the physical issues, they can actually forget how to go. And because dementia can be like a bad electrical connection, it isn’t always consistent. Especially at the front end.

I have often sat with one of my-laws or grandparents and had to remind them how to go. Or try to anyway. That is a hard thing to explain to someone:)

Taipei101, yes, I think it's best to assume incontinence will happen and then if it doesn't you can count your blessings.  As to your other questions about what it's like and what do you do, you go without adequate sleep for as many weeks, months or years as you can, you experiment with many different incontinence supplies to find out what works best and then you try out different remedies as things that used to work no longer work, and you wear out washing machines and dryers.  Finally, you realize you can no longer do all this by yourself, so you enlist the help of many others, either in your home or in your parent's new home in a facility.  Best wishes for you and your mom's journey.

I just googled your question and read that 60-70 percent will have incontinence. My sister can go HOURS without using the restroom (even when I can get her to drink a lot of fluids). I've also read that they don't necessarily get the signal from their brain that they have to go. So in her case, by the time she gets the signal, she can get into the bathroom, but can't get her pants down in time, so she still has accidents. (She also gets a lot of UTIs from holding it too long.) I have her medications set up so she has an alarm go off every two hours. So I tell her the doc wants her to go every time she takes her meds. I often get an argument, but it's helping, except during the night. I realize this is more than your question asked, but thought my "solution" might be of some help to you in the future. Best wishes.

I work at home, and we have one full time aid during my work hours.  We have a doormat type device that chimes if her feet hit the floor.  She can go 5 hours without using the toilet.