Hello, It sounds like the work-up has been done and all the lab results are normal? An X-ray is only minimally helpful - showing constipation. You did not mention fever, so infection is much less likely. Has someone considered abdominal migraines? It s the same idea as migraine headaches, except that instead of head ache you have belly aches. I imagine your GI has considered this. However, the next test I might do - again assuming labs are all normal - is an abdominal CT, preferably during an episode. Finally, have you considered panic attacks? This does not have to be in response to a singular scary or stressful event, but can be a reflection of a kid who is just a worrier, or perfectionist. We don t know why some people seems to have attacks but one thing to ask your son is if he feels doom, or end of the world feelings when it is happening. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Lisa Baker, Pediatrician