How can I make grandma more comfortable?

I posted on her before- though it has been awhile. My fiance's Grandma is almost 95 and was diagnosed with rectal cancer last year. She underwent 6 weeks of radiation and rehab and has been home for about 10 months. Over the last few weeks, she has been increasingly uncomfortable and having increasing bowel issues (very frequent and large volume) She isn't sleeping well due to the frequency. We moved into a new home and we have a baby monitor in use so I can hear her if she falls or needs help. All I am hearing at night is her praying and saying "save me". She is increasingly more cranky and miserable. particularly in the morning. Immodium isn't controlling or easing symptoms. SHe has a doctors appointment coming up- but I don't know what else to do. Her grandson and I are getting married next week. All I can think of is that her time is coming and how our plans will be affected. Selfish I know. I'm sitting here at work, wanting to go home and be with her. But I cant. Any hints, ideas or support is welcome.