Hi Marilyn, Yikes! I hate it when that happens. A few years ago I had a friend in his late 80s that had the same problem but I think his might have been related to taking antibiotics or an bacterial infection. It sounds similar to microscopic colitis. Mayo Clinic has some information on symptoms and causes here - https://www.mayoclinic.org/diseases-conditions/microscopic-colitis/symptoms-causes/syc-20351478. There is also another reference that talks about your question.
-- Microscopic colitis — a common cause of diarrhoea in older adults:
https://academic.oup.com/ageing/article-abstract/39/2/162/40976
You mentioned you are not ill, are taking any medications?