What about the colonoscopy alternative they now offer called cologard? I am doing that instead of a colonoscopy if they are recommending it. Is the issue with your stool still happening? Yes, prolapse becomes a worry the older we get. I'm dealing with that now myself. Sigh. And I've wondered about my stool shape also changing ironically (we have this in common!). It's my understanding that simply being constipated can cause thin, narrow stool as well as ibs. https://www.webmd.com/digestive-disorders/causes-narrow-stringy-stools#1