Rebecca, i just noticed you're on the sublingual B12 - are you getting blood checks to see if you're actually absorbing it fully??
i'm sure you know how it all works with B12 absorption - for many of us, getting B12 into our bodies through diet/supplements isn't the problem, it's the fact we just cannot absorb it due to damage or surgery in one specific part of our intestines.. i have B12 injections 8 weekly at my gp practice - used to be 12 weekly but i noticed i got the deficiency symptoms coming on well before the next *** was due. much better since i have it more often...
on another tack.. i often mention dehydration & electrolytes on here - it's not just that it's one of my favourite subjects lol - it really is so common for us to be low on fluids and/or electrolytes, even if only slightly.. and one of the symptoms is tiredness. i'd recommend anyone who suffers from IBD & is feeling unnaturally tired/lethargic to try drinking one cup of rehydration mixture, powder sachets are available over the counter (Electrolade, Dioralyte etc) and see if it perks you up - just as an experiment. if it does, you have something to discuss with your doctor, and maybe get your electrolyte levels checked. don't overdo it - these levels in our bodies need to be delicately balanced, and too much can cause serious problems, but one cup just to try won't do any harm.