My mom apparently sat on a dining room chair, thinking it was a toilet! What can I say?

Don't say anything to your mother, not if you can possibly stop yourself anyway. She isn't able to learn anything from anything you can say, and all she will pick up from what you're telling her is that she's done something wrong, something she should feel bad about, without really understanding what happened.

Key thing, from your point of view, is to prevent a repetition. I'm guessing your mother is still mobile, seeing as she got herself to the dining chair? In that case, one strategy you could try is signposting: print off big, bold signs with arrows pointing to "BATHROOM" and place them at her eye level along the route. I also used coloured duct tape on the floor for my mother to follow from her easy chair to the bathroom, that helped for a while. Note: don't put anything on the floor that is slippery, or isn't very firmly stuck down - you don't want to create a slip or trip hazard.

If that doesn't work, or stops working, you could try making a bathroom routine for her: help her to transfer as often as you think appropriate, and that way even if there are further accidents at least the volume of "accident" will be limited.

You might need to remove or cover any furniture you're terribly fond of. And you can buy amazingly absorbent, washable pads - there's a wide range on the market, if you look them up under 'continence care.'

Assuming she's in a care home? Nothing. They would have seen worse. They would deal with it and forget it happened. They should have not told you about it that's too much detail. They are used to these situations, you are not. You don't have to say anything. That's why she's in there in the first place so this doesn't happen at home.

Really great answers & suggestions here...if I could add one thing: Sense of humor! Honey - try to joke and laugh about it with Mom. These are very hard times for we children of the elderly - if we don't try to temper the worry and work with a little humor the load will build up WAY past heavy. Good luck & God bless.

How devastating on many levels!

Is Mom aware that this was inappropriate? What was her reaction?

Is mom still in your home? Sadly this does happen
Men in mom's memory care just stand and pee or if an office is open they go take a potty break
I notice mom is now having trouble wiping herself and throwing the TP in the toilet

Hope your chair can be cleaned

People with dementia often do all kinds of things that may seem out of the ordinary, but, it's not that odd really. I don't find it strange at all for a person who has dementia.

If she was at a friend's house, then I'd explain to the friend that mom has dementia and offer to pay for cleaning. If she's in a facility, they see this and worse all the time. No words are needed, except I'd discuss her toileting habits and plans to keep her clean. I wouldn't say one word to her about it, as if she did that, she is not able to process why it was inappropriate and she likely has forgotten about it. There's no way she will learn anything from it. The only way to prevent it in the future is to constantly supervise her and direct her to the bathroom. If it becomes a continuing problem, I'd explore the adult onesies that button in the back and they can't take their pants down.

There are some great videos on You Tube called Teepa Show on Dementia. They cover a host of issues with dementia. I have found them quite informative. I'd check them out. It'll make you feel better about this.

Stock up on a lot of "blue medical sheets".   The sheets will help gather any bathroom oops.   Put the sheets on all the dining room chairs, on the sofa, or any other seats your Mom might use.

You can first try doggie wee wee pads, as those are very similar, to see if they work.   Then search the internet for more affordable blue medical sheets.

I use to order from a company that sold "seconds" meaning the sheets didn't look top quality but still worked.   For me, the sheets were a godsend for a 21 year old cat that had dementia.

And I would also use those sheets when my very elderly parents came over to visit, the sheets were placed under the large towel I had on the sofa, so my parents didn't see them.