I don't believe there's a connection at all....but I think the tendency for AN on an emotional level can interfere with the process of healing (if one believes food has a connection to symptoms in general...and stops eating...or...constantly is worried or distressed about
symptoms).
You didn't cause your UC.
But in saying that....a weak digestive system can be prone to invaders that can set the autoimmune response into overdrive. The tendency would have to be there initially....your own immune system does the rest. We're all open to invaders up to a point...but not all get the autoimmune response as a nice bonus.
quincy