DustyCat....you seem to write pretty much what I'm about to. Lol, I agree, crohns, meds, and like Jenn said, dehydration and sometimes not eating well too. If there's a bacterial issue also, which is common with ibd, then these issues can cause migrain headaches as well, and fatigue etc. But so can just crohns. If flu symptoms with the jheadaches, and relived by hydration, probiotics etc, then look into candida. Many meds can put our bodies out of balance, for me it was prednisone, but most crohns meds are imunesuppressive, and so bacterial overgrowth can become an issue. Best wishes xo