If gluten from cereals like wheat ye spelt etc. make you sick.
Basicaliy Thai people use a lot of rice products. Noodle dishes can be prepared with rice noodles or glass noodles and even desserts might be produced with rice flour. But that is not to be taken for granted. For sure you should avdid yellow noodles,as they are made of wheat flour and eggs. Furthermore wheat flour is often added to soy sauce, which is part of many Thai dishes. An altemative to soy sauce might be fish or oyster sauce and sometimes it is no problem to just leave it out