I tried the SCD Diet which I guess is gluten free since you don't consume any carbs and it did not improve my condition. Not only did it not improve my condition but it actually made me lose a lot of weight really quickly and I became sicker.
I am all for trying it but don't expect it to be the magic cure, especially if you've been tested for celiac and it came back negative.
I do agree with Sue to some extent, you should definitely be looking at surgical options. I know you're hoping for something to help aside from surgery but from reading, I've seen so many people become resistant to Remicade and Humira fairly quickly. I've also seen a lot of people who have not responded at all to these drugs. I hope you have luck with an increased dose of Remicade or with Humira but as Eva said, even if you do, while you're feeling good, you should prepare for the day you stop responding by finding a surgeon you're comfortable with. I dread the idea of surgery because it is an inconvenience but there are some huge positives, being off the drugs, no more unpredicitability, no more urgency... It's hard to accept surgery as the solution because we know it's such a long road.
Have you looked into clinical trials in your area? Sometimes you can find trials for drugs that are not available. Would you try LDN? Strict SCD Diet?