Are they better? You can check them for parasites or bacteria? My son was doing the same, throwing up on and off, now we are running these tests on him. I believe he might have gotten them from swimimg practice. But one can get parasites or bacteria anywhere, especially little kids , they put their fingers in their mouths all the time. It may not be related to gluten or virus.
Let us know how are they doing! Homeschooling four kids! I have a lot of respect for you 🙂