Citrus is another that can be a trigger. And, as I found from my own experience b/f my daughter, spinach is the #1 vegetable allergy! Corn is another really huge one that is in virtually everything :( And, unfortunately, most children who are sensitive to dairy are sensitive to soy (which is really horrible for us anyway unless it is fermented- so no tofu.) Also, some people who are allergic/sensitive to wheat/gluten are also sensitive to even certified gluten-free oats. (There is gluten in every grain- there is just one specific kind of gluten that typically bothers people w/sensitivity.)
I agree w/being very careful about consuming dairy- it's in a lot of things. I could not figure out why my daughter was reacting to rotisserie chicken I was buying at Jewel... but they inject them full of milk to plump them up and don't have to put that on the label! :( There are lots of laws about labels.... for example, if they use a product already made, they don't have to list the ingredients of that product. (So let's say for example you are consuming something with barbecue sauce... the label can say barbecue sauce but not list those specific ingredients.)
The absolute BEST thing to do it make everything from scratch, yourself, and definitely keep a journal of what you eat and what reactions he has. You might even find that YOU are feeling better (that was the case with me!)
Here are some ideas for food within the guidelines you mentioned:
Breakfast-
Bob's Red Mill Gluten-free Buckwheat Porridge made w/water, sea salt, sprinkled w/chopped apples, a little organic maple syrup, and flax seeds if you want sweet; for savory, add some nutritional yeast (sold in the supplement section at Whole Foods), herbs and spices.
Homemade sausage- http://chickiepea.wordpress.com/2010/09/02/make-your-own-...
Coconut milk yogurt (best to make your own since store-bought has a bunch of junk)
Lunch/Snacks:
Lettuce wraps or homemade spring rolls made w/rice paper wrappers (watch these for wheat/gluten!) filled w/shredded veggies, sliced chicken or beef and homemade or goddess dressing
Hummus w/fresh veggies
Freeze bananas and then peel and chop w/sharp knife. Put in food processor w/tiny bit of coconut milk or water and puree until you get "ice cream"
Homemade soups and salads. Dressings can be made w/coconut milk, rice-milk, avocado to add a creaminess. Watch out for stocks/broths, as they usually have additives and wheat if you buy them store-bought.
Dinner-
Roasted veggies, fresh veggies
Any meat as long as it's not breaded OR get creative and used ground up plain rice-cakes or potato chips (look for those cooked in safflower or sunflower oil- the alternatives can be allergenic) w/some herbs and spices.
Spices are best bought gluten-free, as some companies use wheat so the products don't clump. A lot don't specifically say it, but you can find the info online or by calling.
I'm happy to help you modify recipes, if you have anything you are specifically going to miss (for free, of course!) We have done lots of diet mod for our family over the past few years. The best resources I have found are to look at vegan sites for recipes (those are dairy-free, obviously) and most raw vegan recipes are gluten-free.
Another tip to help avoid dairy in processed foods is to learn the kosher symbols for dairy-free "Pareve" means it's contains neither meat nor dairy, and "Parve" means it contains no dairy.
http://www.godairyfree.org/Food-to-Eat/Food-Label-Info/Un...
Hope this isn't completely overwhelming- I was trying to be thorough! Feel free to message me or contact me through my food blog too:
www.chickiepea.wordpress.com (Everything there is gluten-free and most have a dairy-free option, though most snack and baked goods are heavy on nuts. It shouldn't be necessary to cut out coconut (which can be useful on a dairy-free and gluten-free diet) unless you do discover a true nut allergy and it is recommended by your dr.)
A good children's chiropractor might also be of help, as it was with us- when things are in line, the digestion becomes much better.
M.