My mother-in-law has cancer. We are keeping her at home because that is her wish. We have hospice as needed. She is eating and drinking very little and sleeps a lot. She has not had a bowel movement in 5 days. She will go to the bathroom to pass urine but has to have help. With the type,of cancer she has we were told she would starve to death. The cancer is concentrated in the bowel area.
If she's not eating, there isn't going to be much to pass anyway.
I am so sorry for the sad and traumatic situation your mother-in-law and family are facing. I hope that her eventual passing is as peaceful and pain free as possible.
Peace be with you and your family.