I agree with all of the above, except World Healing. I think he definitely needs some stool samples as well; he could have c. diff., salmonella, parasites, etc. It's pretty common for Crohnnies to get those.
Also, there is a blood test that can measure the level of Remicade in your husband's system. It's a bit pricey and not many insurances will cover it. It's called the Prometheus test. But he would do it right before a Remicade infusion, and it will tell if there's any Remicade left in his system, if he has antibodies to it, etc. I get 10 mg/kg (a double dose) every 6 weeks, and that finally got my symptoms under control.
And contrary to what your doctor says, food DOES make a difference! However, if just one bite of something is causing a full-on flare (needing steroids to make it stop) as opposed to just a day or two of symptoms that resolve on their own, then he's really not stable enough.
Also, not to do with the fevers, but it IS possible to get IBS in addition to IBD. Has he tried any medications like Immodium or other IBS meds? That might help some of the symptoms.
However, please keep in mind that while he can most likely get into remission, he will never regain 100% of his health. Just the nature of Remicade and other Crohn's meds, he'll get colds easier that will last longer, he'll have days where he just feels worn out for no reason, etc. It's hard to adjust to that reality sometimes. But you CAN have a very good quality of life, if that makes sense. What he's going through right now is not normal for having the disease under control.
Lastly (sorry, just throwing out all the thoughts in my head, lol), is he taking any supplements? It's super easy to get fatigued from Crohn's because your absorption levels go down. It would be good for him to take a multivitamin, iron, calcium (especially if he goes on steroids sometimes), vitamin D, vitamin B (especially B12 and folate)....those are the ones I take. It might help his fatigue level.
"For this thing I besought the Lord thrice that it depart from me. He said, My grace is sufficient for thee: for my strength is made perfect in weakness. Most gladly therefore will I rather glory in my infirmities; I take pleasure in infirmities, reproaches, necessities, persecutions, distresses, for when I am weak, then am I strong" 2 Corwww.thecrazyshoppingcart.com/