Hi Michelle,
After your reading you thread i think you are on the right track, I would not be treading lightly when it comes to ED's. Dairy free and soy free is hard enough. I would only be going for further food eliminations if the poos were constantly mucusy.
Personally, I feel that if the reflux is food driven, then mucus nappies and additional food intolerance (lower gut) symptoms should still prevail along with the reflux symptoms. THat is just based on my experience with Ds2. If the poos are explosive or girgling or verty watery that can be a sign of gluten issues, but it sounds as if her poos are pretty good on the whole.
I was started dairy free soy free from birth. Then went to wheat free at 3-4 weeks old based on his poos, he definantly had some major gut fermnetation issues and lactose overload going on with bubbling, watery, foreceful loose poos. After being on that diet for a while we were still getting runs of a week or so of major mucus nappies with green in them, and his reflux would go off the charts during these episodes. I knew that DH had suffered from allergies to tropical fruits as a child so I always had salicylate intolerance at the back of my mind. Anyway he was bad enough that I decided to do the low chemical diet (RPAH diet) to try and rule our food intolerances to salicylates and anything else. Once I got him on that diet it took 6 weeks or so for the poos to settle to perfect. I started working through food challenges, I found that he was ok with amines, but not salicylates. He also was reacting to some preservatives and additives. The deitician advised me that if they start failing a few preservative and addtive challenges and are also alreadys sensitive to salicylates, you can start assuming senstivity to the untested foods/addtivies, as we had a sensitive LO on our hands!
Anyway, I think the main issue with ED's is that is is very hard to exit from them. You reach a point where they are good and reaction free, and you have a fear of new foods. It is extremely hard to introduce foods or do food challenges in a scientific manner with nothing else going on to throw out your results - teething, sickness, shots, introducing solids to them directly. So I got into a limbo land with my diet and had to keep mine fairly strict so I could introduce more foods to him when he was starting solids. You can only do one thing at a time and you need extreme patience! You need to wait for reactions to finish, and then 3 clear days. In the end I only was able to eggs when he was about 8 months old, yet he probably was able to tolerate them alot earlier, however I couldnt get round to the food challenge, it was lower down on the list. So I probably suffered egg free for a good few months longer than i needed to.
So my advice would be if you ARE going to try cutting foods, start with one or two likely culprits like wheat as Liz suggested.
And I was only able to stay on my diet so long because I had major help from my people coming to cook for my freezer