I hate to hear this. My daughter goes through this from time to time when her sugar is uncontrolled. We had this episode just about 2 weeks ago and this wasn't the first time. She had all the test done that you could think of and they saw nothing.... The doctors are saying that chronic stomach pain stems from have high sugars for a long period of time. Once the sugar is better controlled, the stomach problems will subside. I promise, we go through the same exact thing from time to time and it is awful. I hope your child gets better soon~
I would ask the doctor to run the test for celiac. Many diabetic children do have celiac, and rather than just assuming that he is too young, if I were his mom, I would ask to have him tested. Also, you may want to look at food allergies. Allergies can cause a child's adrenalin/cortisol levels to rise (that's what the body does to fight off allergies), and the result of high levels of adrenalin (which is insulin-resistant) is high glucose levels. Your son may be allergic to dairy products or to wheat, which is a totally different problem from celiac, which is the inability to break down gluten. You may want to try removing some of the commonly allergic foods from his diet, one food at a time, to see if it helps.