I have to wonder if sometimes it isn't us "Crohnies" that put the guilt trip on ourselves when we have to miss work. I feel terrible guilt even though my boss is awesome and never complains when I have to leave early or call out sick. But I still feel so bad that I talk myself into believing that she thinks I'm faking sick...ridiculous isn't it? I recognize that I do that to myself with no help from outside sources...haha. So I tell myself to stop feeling guilty and beating myself up...I am sick otherwise I would gladly be at work, all of us here have a serious disease which takes a heavier toll on our bodies than I ever would have ever imagined. Maybe some supervisors don't understand CD and what it does to a body but there is actually really great information on the web about how to talk to your boss about this disease, I found that helps so much now that my boss understands about my illness.
Hang in there and try not to feel guilty, that only adds to your misery :)
Take care all and have a great new year!