Mother-in-law loves having diarrhea. How do I handle this?

MIL had to be moved out of her house out in the country to a house that we bought in town. We built on a handicapped accessible apartment for her so she has her space but is close to our son/dil/grandkids until we are able to move back. We are currently living in Norway with my husband working for NATO. She got diarrhea about a year ago and I took her to a GI doctor who told her she had to have a colonoscopy to figure out what's going on. She refused. He said he can't help her then. She said fine. She hates doctors and believes that they kill people. She is over weight, slow moving and falls quite a bit. When she needs to go, she just goes where she is. In the grocery store as she's walking around, in the car on the drive home. She's pooped all over our sidewalks. Doesn't care. We refuse to take her anywhere now and she's mad. Her keys were taken away from her last year. We told her if she wants to go to the grocery store instead of someone picking up her groceries, she needs to fix this. She said she's lost 75 lbs since it started so she has no desire to have it stopped. We have someone come in and clean for her twice a week (really needs to be everyday but can't find anyone to come for an hour everyday just to clean up poop) and on Tuesday last week they found her laying flat on the floor. She slipped in poop, her feet went flying up and she slammed her back into the floor and couldn't get up. She has a life alert but doesn't like wearing it so no one knew. She also doesn't like to take showers. She is being FORCED to shower twice a week because the smell is horrific and she's very upset about it. I'm at my wits end. She was in a hursing home for a week after a surgery for an impacted intestine and we really hoped it would fix the problem but it hasn't. After the surgery, her apartment wasn't quite ready so she was in a nursing home for about a week. The nursing home said she does not "need" to be there so she had to pay out of pocket. I'm at a loss. If someone goes to her house, sees poop everywhere, smells how bad she is, I'm afraid social services (or whoever does that) might show up and accuse the kids staying with her of elder abuse. She thinks they meddle too much (taking out the trash, trying to clean up the messes) so she locks her doors and will not let them in. They pick up the meals on wheels for her everyday and she won't even let them in to deliver it. Has anyone had something similar to this happen? If so, how did you take care of it? Oh ... she REFUSES to wear diapers because she's not a baby (even though she acts like one)