Too bad there isn't a legal intervention for laxative abuse! My mother is in independent living (shouldn't be but refuses to move). Like a lot of old people, she is obsessed with her bowels. To complicate things, she has dementia and doesn't remember what she did 10 minutes ago. One minute she says she had diarrhea and an hour later claiming she hasn't "gone" in 3 days. Therefore, she is taking this laxative more than once a day, obviously. We have tried taking it away, but she just goes right to the in house store and buys more. Since she is in independent living, they can't refuse to sell it to her. There is no reasoning with her, with anything, we have tried everything and so has the doctor. We just keep hoping that whatever health crisis this causes, it isn't too serious and will force her into assisted living.
You don't say who has the durable power of attorney. That is the person(s) who has the decision making power about this. Everybody else in the family is entitled to opinions, but they don't get to veto a move. I'd say mom's behavior is an indicator a move is MORE urgent, not less.
Get her into the right facility as soon as possible and let all her negative and threatening comments go out the other ear. Don't wait for a crisis because a crisis means you won't have choices or time to think. Do it the way it will make it easy on you. Your mom is never going to have a "better time" where a move will be easier.
The way you get your mom to move is to just move your mom - sounds silly but it's not. "Just do it". Take action, end the old lease, start a new one at the AL, and coordinate move day. Make sure your mom is somewhere else for the packing & unpacking bit. I had to do this with my mom. She was not part of the process. She couldn't be - she was not mentally or physically able to do anything but obstruct. I explained what was about to happen in the short term to her, but she never got a yes/no vote on the move or timing. It was treated like a done deal from start to end and I focused my time & energy on executing the plan. If mom were more mentally able, I would have included her in more decisions. But I would not have asked my 6 year old which daycare they thought they ought to be at and when would be a good time to go. She tried to delay the movers at her old house by refusing to pack up her bedroom. I told the guys they had my permission to shrink wrap her to the bed and stick her on the truck! Ha! We ended up only getting some of her bedroom packed because she wouldn't get out of the way. We did not get 100% of it though, and that's the way it played out. What we left behind was not important enough to worry over. (Mom was a clothes hoarder.)
As far as the MoM goes, if this were my mom, I'd go into her bathroom to "use it", and dump all the MoM down the toilet while I was in there. Leave just enough in the bottle to water it way way down, so she still gets the MoM taste and thinks her bottles are full. Yes, this is deceptive, but her safety comes first. I'd keep watering it down a little every time I'm over there. I also deceived my kids that they were eating full price Captain Crunch cereal when the box contents were the generic equivalent! We have to do what we have to do in order to look out for their safety and security above all else. I flipped the breaker swith in my mom's apartment so her stove won't even come on anymore. :-D Keep us updated on how things are going!!