Nancy-
As I remember you writing a few months ago, you had a few food
allergy tests for Tyler- for the main allergens. I don't remember if
I wrote this to you before- but my son would also have chronic
diarrhea and stopped growing by 18 months. We did a more extensive
RAST test, and learned about a barley allergy. He also  chronically
had a bloated stomach. I remember you also doing at least a bit of a
food /symptom diary..For my son, he craved the barley items (and
dad's Chili) and the food would come out the other end usually within
3-4 hours. Is there a food Tyler devours? Would it be possible to cut
back Tyler's diet to only 5 foods, and reintroduce them- only 1 a
week?

My daughter, on the other hand, when I gave her potato chips with
corn oil- within 5 minutes she'd be cranky. There are some kids who
get irritable with food colorings and preservatives. see
www.Feingold.com for more info.

My son, after eliminating barley, then wheat, then oats, and corn- we
learned that adding some thiamin to his diet helped the loose stools
(and more bananas and oatmeal). Milk is constipating for some people,
so eliminating milk causes looser stools.