That’s one of the possible graft vs host maladies. That is, there are three typical manifestations of graft vs host: skin (rash, which we’ve seen), liver, and gut (n/v/d = nausea/vomiting/diarrhea). On the other hand, it’s possible she simply picked up some sort of stomach virus and her immune system just can’t handle it yet.
Really, this is all we know at this point. We’re still well within the first 100 days, and so we’re well within the time that acute graft vs host can be an issue. There’s still the possibility for chronic graft vs host, after day 100 through the end of the first year.
Last time she was in the hospital, and having gastrointestinal ailments, they had talked about giving her a colonoscopy. Her symptoms eased up, and so they didn’t go through with it. I suspect they might do that this time. So she’ll likely be in the hospital all weekend, and into early next week.