Mother eighty six years old has not eaten for six weeks and now having and endoscopy why?

I'm not a Doctor, but I am an undergrad student with a Pre-Med Associates doing Molecular Biology BS and studying for the MCATs. I presume by saying that "she has not eaten in six weeks" is that she hasn't eaten much? People over the age 40 should have endoscopy as directed to ensure that they is no cells growing abnormally inside the G.I. and so forth. Hope that helped.