meyerlemony,
Stress is a huge issue for me as well... i tend to be a "dweller" where i stress over everything... this does not help my UC, then i stress about my UC... you see where this is going :) From what i have read/been told, is that stress etc increases the amount of inflamation in the body and affects everything.
As for dealing with it... not sure, cause i struggle daily with this and think that it may be keeping me from or slowing down my recovery. my wife has in the past given me a pill or two from her clonazepam (very low dose) and that helps take the edge off so to speak. there are a number of stress releasing excerisies as well, just look on google, that i do... ie deep breathing etc.
hope this helps :)