How often BM when not eating?

Hello all, I'm new to Hospice nursing and actually work on the community education/marketing side. That said, I've been a nurse for 6 years on a Med/Surg floor of a hospital, but find myself with questions re: hospice patients and care. Add to that, we recently put my MIL on Hospice and moved her to our home to care for. She has advanced Alzheimers and is total care, bed bound at this point. She may drink 1/2 can to 1 can of Ensure per day with sips of water and maybe 5-8 small bites of food total. Often, she says she's just not hungry or just shakes her head no. I'm okay with that. I get the whole decreased appetite at end of life reality. However, should I be concerned that she hasn't had a BM in 6 days? Abdomen is soft, non-tender, non-distended. Bowel sounds active. So.... with as little as she eats, how often should I expect a BM? Your help is appreciated. I have MOM and glycerin suppositories on hand and thought I might start with some MOM.