My 7 year old has been having bad stomach cramps for about 3 months. About 4 times, she has thrown up. She had a RAST test and an upper and lower GI this week. They showed no problems. However, she had just finished a 10 day course of antibiotics for a double ear infection 2 days earlier. I have read that antibiotics before a RAST test can skew the results. Have you heard that? Just searching for an answer. My other daughter is allergic to dairy and all nuts. I was thinking this might be the same. Now they want to say it is IBS because they found nothing. Just wondering if I should have a back test done.
It sounds like she has problems sort of like mine. In my case the problem is food sensitivities. These are not allergies, I'm completely negative to both the skin and RAST tests. Likewise, as the reaction doesn't involve the IgE pathway antihistamines do absolutely nothing. The only thing I have managed to learn is that the mast cells are involved as a mast cell stabilizer (Gastrocrom) does reduce the symptoms.
If I didn't know what to avoid eating it would look like a bad case of IBS-D.
To test this hypothesis I would suggest trying an elimination diet.