Coeliac is managed by a gluten free diet. At this stage, there is no medication or treatment. The thing is, if your DS is coeliac, continuing to feed him food containing gluten (such as bread and oreo's) is doing more harm than good. It destroys the villi in the gastro intestinal tract (I think you may have already mentioned that his villi were flat on biopsy) and he will not absorb any nutrients from the food he does eat (including iron!). Not only that, there are long term implications such as greatly increased risk of bowel cancer. Although I'm sure it is reassuring to see your DS at least eating something, IF he is coeliac he will feel quite unwell after he eats foods containing gluten. I imagine this creates a vicious circle where your DS doesn't want to eat because it gives him a belly ache and makes him feel sick, so he only eats things he really likes - such as oreo's or dry cereal - which contain gluten, which makes him feel unwell, so he doesn't want to eat anything other than the things he really likes the taste of - such as... you get the idea.

I am in no position to diagnose your son as Coeliac or not, and I assume you are seeing good doctor's with experience in gastroenterology. It is my understanding that a bowel biopsy provides a pretty conclusive diagnosis as to whether a patient suffers Coeliac disease or not and the primary indication is flattened villi - which your son has.

Although you have said that your DS wouldn't eat anything on a GF diet, sometimes we have to be cruel to be kind. By denying your DS oreo's and the like (IF he is Coeliac) you are preventing further damage and allowing his gut to heal. There are many, many GF alternatives to 'regular' foods - including yummy bikkies. In time, your son will find GF foods he enjoys, particularly if he finds he doesn't feel unwell after eating them!