With I'm classed as in remission when I'm not poorly and my bloodtests show no inflammation. Remission also used to mean for me having no symptoms, unfortunately a few flares on I will now always have trouble with my bowels due to damage somewhere along the tract, I get diarrhoea every morning but its controlled with codeine for the rest of the day.
My GI usually waits until my results and good health have been consistent for a few months before using the term remission, during the time its referred to as 'quiescent'. My last scope showed inflammation but it was still in the process of healing (that was 2months into a quiescent period) but my GI just said that that just showed how severe the inflammation had been in my previous flare but was confident it was definitely going into remission, 6 months later still going strong!
Theres some foods I will never be able to eat without a problem, fruits and veggies I can handle in small quantities but its not necessarily active disease that will be causing issues with it, it could be due to a bit of damage/scarring from previous flares or just that your body gets so used to being played safe with it just doesn't know what to do when a bit of fibre is thrown its way!