How do we break the news to my mother-in-law that she will never return home?

Giving hope is often better than being honest.

Why don't you start off with "You just need to stay here for a couple months, so they can make sure you stay healthy." Then just keep increasing the time. Telling elderly it's only for a little while, rather than forever is a lot easier, and it doesn't overwhelm them as much.

Even with dementia my mom cried in the moment when she understood she was in a facility forever so now I do my best to avoid even answering where she is when she asks - why cause her more unnecessary pain

Honesty is not always in the best interest of an elderly person and having hope is pretty essential

I agree that it's probably best to say it's for a few months, at first.

I think I'd throw in something along the line of - "you're still medically very fragile and your doctor doesn't want another situation where you go home only to return to the hospital a day or two later - like this last time. It's important that your strength get built up and we know for sure that the c-diff is under control. Returning you home too soon could be very dangerous for you. We love you very much and don't want anything to happen to you."

Good luck to you - it's a tough situation to be in.

Say that 'we' are listening to the doctors on this one Mom, until then, 'we' will take it one day, one week at a time. We will be here to help you get better. Now, what do you want for a special treat tomorrow?

Sometimes the most truly righteous thing to do is to tell little lies such as outlined by several in the foregoing comments...

After caring for my wife at home for nearly 24/7 for two years my heart gave out. She had experienced a massive stroke. After two months in the nursing home I realized I could no resume giving her care on my own due to my health...I told her that the doctor said I would die if I continued to take care of her at home (In fact, that was a lie.) She rebelled vehemently, but after a day or so she accepted it graciously. ...She has no dementia and is very sensible and loving. by nature. That was in 2007. From that point forward, we spent north of a half million dollars on nursing home fees and she finally qualified for Medicaid....I visit her twice daily to assist her with eating and I hire a lady every day of the month to visit and assist her for the supper meal. She is very happy...

You may want to soften the language of saying " few months" to a "few weeks" but I see the "gradual" approach as being sensible.)

Grace +peace,

Bob

Thanks to all of you for your suggestions. My husband will be the one to try to answer her requests since he visits her while I'm at work. I suppose that just the way we're better off not arguing with her when she has periods of hallucinations (not sure what triggers them) we're also better off not telling the full truth about going home but trying the approaches that you have all suggested.

I would lean very heavily indeed on delaying tactics. For example: "let's see how we get on"; "we're doing our best"; "the doctor says we'll review at the end of this week/next week/the month" [or however long you can get away with]; "your blood tests still aren't right, I'm afraid. You need to get a bit better yet."

I can't imagine circumstances which would make it ethically or practically essential for you to spell it out to your MIL in terms that she will never go home. Expressions of time such as "for now" and "until you're stronger" are so usefully extendable and ambiguous. But are there reasons for needing clarity that I haven't thought of? Do you need her consent to a house sale or something?

Good advice here as always. I found with my mom that I had to just take each day as it came. I never talked days, weeks or months; it was always by the day (singular). When mom ended up in the ER for the first time, (which there have been many since) the doctor said she was no longer able to live alone and they would not release her to go home alone. So I had her move in with me because it was the best choice and none of the other siblings were willing.
Her routine was kept intact during the day which was going to the restaurant and doing what she could do of course, over time with dementia that ended. But there was enough time in the interim to ease her out of her routine at the restaurant. To where eventually she could not go to the restaurant anymore and I had to bring in outside help.
I would pick her up at night to take her home. I would answer her question of why I was picking her up with saying I don't like to stay alone and would really like her to stay with me if that was ok. And she almost always said ok. On the other days when she didn't say yes, I waited for 10 to 15 minutes and asked her if she was ready to go and she would agree to stay. Eventually, she stopped asking and was more than willing to go home with me.
I would imagine in your case with it being a nursing home that the advice above about saying the doctor just wants to have you stay another day to make sure you are ok, would be the best way to go. Perhaps, change up the way you say it from time to time and over time she will probably stop asking. Some people ask every day for years and others don't, so it's hard to say in your case.
My best advice is to take every moment of every day and live in that moment. Get creative with your responses. Never say never.
Good luck and take care of yourself.

The words 'safety' and 'attentive care' worked for us.. tough situation. Honesty is always best but do realize not always when it comes to the elderly. A nicer 'version' of the truth should work. Good luck. :-)