Bowel Incontinence With Dementia Patient

My 85 year old mother has advanced dementia and I am her sole caregiver. Recently she has been digging her diaper and smearing it all over herself. Her bowel movements are erratic too. She will go for a few days without having one at all and then as if a switch was flipped on she will have bowel movements non-stop, all day, all night, every day. Not diarrhea but soft. I understand that dementia patients don't like the feeling of feces in their pants and this is why they try to remove it but I am about to lose my mind. I caught my mother digging in her pants while she was laying her recliner and this has happened several times. Every single morning when I walk into her bedroom I find that she has smeared feces all over herself with both hands and smeared it on the wall and bed clothes. I have to bathe her every morning now and wash her bedding every day. This is getting really really old. I am already burned out from taking care of her for six years and I am 60 years old. I am to the point where my mother needs to be placed. I've researched 'onesies' for adults and incontinent clothing for Alzheimer's patients but the outfits are outrageously expensive. Why does my mother poop so many times a day and night? I haven't changed her diet at all and it isn't as though she's getting a lot of fiber either. I go through a large pack of large wipes per week and a box of latex gloves every two weeks. This is insane.