I have read that it takes about 3 months for the gluten induced antibodies to drop to a normal level after stopping eating gluten foods. So if gluten is causing the problem relief may be slow to come.
When a gluten intolerant person has been off gluten foods for years it also takes time for the antibodies to build up in some people. I read the story of one guy who mother kept him gluten free when he lived at home but then he went off to college and ate whatever he wanted. It took a few months for him to start reacting and become convinced he needed to stay off gluten foods if he wanted to be healthy.
It is almost irresistible sometimes to not eat all those wonderful smelling and tasting gluten foods. What helps me resist is that I ordered the test for the dna marker and it came back that I do have a main Celiac gene - HLA-DQ8.