The symptoms you describe--headaches, asperger like behavior, gastro discomfort, smelly stools--all are big indicators of celiac disease. Our daughters got diagnosed and had all of those symptoms. Strangely enough, I only found your posting b/c my 5 yr old daughter (gluten-free for 2 years) is developing grey spots in her eyes. Very slight, but definitely there, in the outsides of both eyes. And to read HER symptoms of her already diagnosed disease in your posting makes me wonder if your son has celiac as well, and that the spots are just something that goes along with the disease. It's a simple blood test and the disease is the most common auto-immune disorder there is (more than diabetes, autism, MS). One in 133 in the US have it but few know it. Check it out! I'm very curious--can you post back here if you find out whether or not he has it? Good luck!