How do you get an incontinent person to wear adult diapers?

Try Healthdri washable diapers. They are made out of cotton and are reusable. While the maximum absorbancy ones are super think like disposable underwear, the moderate ones are much less bulky. Because of that and the fact that the are made out of cotton, they are much more like regular underwear. Also, they are much tougher than disposables so that they can't be ripped apart. My mom and grandma shred disposable diapers casting those absorbent beads wide and far. Healthdri is not cheap though, $25-$30/pair.

My Mom uses Flex-fit too. We dont call them diapers or depends. But disposable underwear. She has her pride and it took us a while ( although it was mostly for leakage with constipation) But she wears them all the time now . They look like undies and are tan not white . Additionally you can tear them off which makes changing easier

The depends type underwear are really great. Dealing with accidents while out
in public is both embarrassing for them, and back breaking for you.

Repetition is key. Matter of fact manner helps too.

I am appreciating these suggestions.

We are struggling with a similar problem. My Mom forgets that she leaks and has accidents, so as a result she sees no need to wear pads. She isn't completely out of it, so we are hoping that soon it will "click" that she really does need something - other things have clicked with enough repetition. Otherwise we will have to have a serious talk, and maybe replace her underwear with "absorbent underwear", and she wouldn't have to remember to use pads.

We went through the balking at incontinence products until my father had a series of
very embarrassing accidents. Then we went to flex fit, but finally even they weren't
enough and we went to heaviest coverage product which did look like a diaper. But
by then he didn't care as he was more worried about not soiling his clothes.

I called them absorbent underwear, and stressed how much he wanted to keep his
clothes clean and dry. I also got him velcro fastened shirts and pants that had faux
buttons and fly which looked like real thing. He still needs help dressing but feels more
independent and care givers appreciate having things made easier for them, as they
have to deal with his frequent incontinence.

Have a look through these. There are many types of disposables that look like real underwear, some of them claim to feel like real underwear.   There is also washable incontinence underwear, but I don't know how well they'd do with feces.  My mom has a "loose bowel" problem, so we buy Depends Flex-Fit - which actually does fit well and (the women's version) resembles beige high waist briefs. 

www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=incontinence+underwear+men

These, for example, claim to look and feel like cotton underwear, and you can order a sample pack:

www.amazon.com/HASOCARE-Breathable-Incontinence-Underwear-Trial/dp/B072284ZTH

Also, definitely don't call them diapers in front of the person. That just upsets them and makes them more resistant. I think the idea of using a "diaper" must really wreak havoc with an adult person's self-esteem. ESPECIALLY men. Women become accustomed to wearing menstrual products like pads early in life, and also many women come to accept a little incontinence after childbirth. Men generally don't have to deal with "down there" issues till later in life.

Album,
Have him put on the Depend THEN put the boxers on over the Depend. That will look how he's used to looking.

My Mother calls them diapers. I don't know why. She has an internal catheter, but it only catches about 80% and she leaks constantly. Our biggest problem with her is that she's cheap and tries to make things last far longer than they should. She wears a "diaper" and very thick absorbent pad inside that. Still, even with those and the catheter, she will often have leaks--ad she cannot control them. I ought to see if she could get a more absorbent brief--she's so concerned people can "tell" she's wearing a brief, but the smell alone is a pretty good giveaway. She CANNOT SMELL ANYTHING--so her place is really ripe. I'm sorry to say, I gave up trying to get her thicker briefs and working more on her being "aware" that she can't just keep putting more and more pads inside the brief--at some point, she HAS to change them.

My FIL WOULD go commando--he wore thong type underwear and that's all he owned. Was both bowel and bladder incontinent. Too many gross accidents in restaurants left behind for ME to clean up--I threw out every pair of thongs and replaced them with the thinnest brief I could find. DH would NOT discuss this issue with him, so I did. It was awful--so I have no profound things for you to tell you LO about needing this extra level of care. It was embarrassing and humiliating for both of us. The nurses in the hospital gave him no wiggle room , he HAD to wear briefs when in the hosp.

Looking back I should have literally forced my DH to step up. He was so skittish--anything the least bit "gross" and he'd be dry heaving. I didn't do him any favors by taking such good care of his dad--well, that's not true. I made it possible for him to have zero accountability in his dad's care.

My dad has no dementia but frequent loss of bladder control. Both his primary doc and his urologist have told him repeatedly that at his age, and with his other medical conditions, there are no meds and no surgery to help the situation. His best option is depends. He has several types we’ve bought to choose from. He will wear one when he’s going to be out of the house for a long time or attending an event. But he’s still quite resistant to them. For him it’s a combination of feeling like the use of them is “giving up” and being a depression baby and being hyper aware of the cost of them. We’ve caught him saving them when he didn’t fully wet one!
So perhaps it may not be all about the look of them? There are some that look very close to underwear, but contingent on where your dad is in the dementia, there may be other factors to his thinking

Similarly, I found it a small but real relief to think of these products as being for continence care, as opposed to incontinence. They are aides which assist a person to be effectively continent.

Yes, mere words, of course. But words are thoughts and the brighter the side they focus on, the better.

Back to the actual point: Alium, you say your father has *early* stage dementia? So is there another cause for the double incontinence? Do his doctors not have anything helpful to offer?

Terminology is very important as Ahmijoy said. I know it's easy to say "diapers" but diapers are for babies.

"Briefs", "Depends" (other brand name), "undergarments". etc.

Great advice from Ahmijoy. For my Mom, I had to help her dress. She didn't want to start wearing the Depends. I told Mom her mattress was new and we didn't want to chance it being soiled. When she protested (lightly, Mom was an easy soul), I was just firm (lightly). Over time she still mentioned not wanting to wear them, but I would answer, "I know, Mom. I wouldn't want to either, but you have to protect your mattress [insert "new chair", or "my car seat", ...].

Alium, my own Dad used Depends Fit-Flex that look more like regular underwear.

One thing we had to do was to remove all of Dad's regular underwear so he had no choice but to use the Depend type garment. I doubt at an older age that a fellow would go "commando" and not wear underwear at all.

One thing, these type of garments can become very warm to wear. My Dad use to complain big time even when he wore a Depends Guard pad for urinary issues. Being a woman, I couldn't feel sorry for him, welcome to my world.

First, do not call them “diapers” or “Pampers” to his face. This is demeaning to Seniors and can make them think you view them as a big baby. There are pull-on briefs that look like underwear. Some are for men and some are for women. They can be ordered off the Internet or bought in a store. I like Tena for my hubby, but most are the same. The men’s version has extra padding in the front. It’s been suggested here that you replace his regular briefs in the drawer with these.

Without being patronizing to him, focus on the fact that he can dress himself and what a big help that is to you.