What helped me tremendously to stop diarrhea and calm my intestines was the eating protocol by Elaine Gottschall in the book Breaking the Vicious Cycle: Intestinal Health Through Diet (I have no connections or financial interests). Her theory is that some enzymes are missing in celiacs, and we therefore can't split up complex sugars. These sugars then stay in the intestines and form a breeding ground for bad bacteria and fungus. She gives lists of what to eat and recipes and also what not to eat. And part of her protocol is 24-hour yogurt.
There is also a list of these foods here:
I would recommend to get the book from the library and to take a look. I started to do it in 2014 and did it for 2 years. After that I was able to eat some of the "illegal" things (but gluten free) without problems. I still mostly stick to this plan, simply because feel really well when I eat this way.