Shitty grandma

So my mom who has my sisters 3 boys 5, 6, and 9 years old moved in with my grandma ( her mom) last year after she fell and didn't want to be put into a rehab facility. My grandma was a severe drinker. At 76 years old drinking a case of beer a day and also taking xanax(4 times more what she was prescribed) pain pills and sleeping medication all while drinking. My mom got her to stop drinking and she replaced it with icecream and prunes. Now she has moved from that to drinking 5 bottles of anti-diarrhea medicine a week. The past few months she has started to purposely poop her pants when someone else gets up to use the bathroom. We will ask if she needs to go and then when someone go in she will imminently stand up and poop all over her self. When she does go in the bathroom she poops all over the toilet , floor, bathtub and then smears it on the walls. My mom cleans it at least 5 times a day with bleach . my grandma doesn't see a problem and will also go a week or more with out bathing after she has these episodes. When someone says anything about it to her and that she needs to bath she gets defensive and tells us we're ganging up on her and she feels unsafe. My mom waits on her hand and foot. My mom finally yelled at her today that she needs to bathe and the bathroom is unsanitary for anyone especially the kids and she told my mom she was crazy. I don't know what to do. My grandma will call the rest of the family and say she feels unsafe when we try to get her to clean herself. What would you do in this position?