Have you worked with a nutritionist ? My attempt at LowFodmap was a disaster when I was doing it on my own. Even yogurt gave me diarrhea. The nutritionist took me off dairy also. It has taken a while to tweak it but it seems to be working now. I am also off grains and most complex carbs. My initial diagnosis was suspected CDiff but I ended up with a SIBO or dysbiosis diagnosis, which may also help account for why we may be reacting to the diet differently. Best wishes to you.