I'm no doc either but I would really work on helping try to restore her intestinal balance which might help with the diarreah.

My mom has some issues in this area and we have her eating fresh pineapple every day, plain yogurt without any sugar (sugar helps the bad bacteria thrive and outnumber the good bacteria in the gut), and smoothies made of unsugared fruit concentrates diluted with water, fresh fruit, with maybe some carrots or kale thrown in. She really doesn't like the kale but it is so good for us I put it in there anyway. Yogurt is really good for our gut so I'm trying to get her to eat this every day.

I've also cut out wheat products substantially as I have read over 40% of people develop a sensitivity to gluten as they age, as well as milk, cheese, butter, and of course anything processed. I want to be sure her issues are not being caused or aggravated by a food sensitivity, and as she goes on we can gradually re-introduce a food into her diet: if she reacts badly, we know to avoid it. We just started this regime so I can't say it works but it can't hurt, so we'll see.

If you look up pineapple you'll see it has bromelaine in it, which is very healing for the gut. Maybe this can help your mom, good luck.