Some people have both IBS and IBD. I do. I had IBS for more than 10 years before I got IBD. I differentiate the two depending on symptoms, time of symptoms, and duration of symptoms. For example, I ate a bag of sugarless licorice once by accident. I didn't know it was sugarless. My body overreacted. It produced so much digestive juice that it sounded like a thunderstorm inside my abdomen. I had sever diarrhea and urgency afterward. However, once the licorice went through me, I was all better. With IBD, once the food goes through me, I'm not all better. My condition does improve when I avoid certain foods and eat certain foods. But I'm not all better. Plus, with IBD, I have blood due to ulcers. I don't get blood with IBS.
It could be that you have both IBS and IBD. Many of us do. Try keeping a food journal to distinguish the two. Eating the wrong foods could also trigger a flare for some people; so it's very important to avoid consuming foods and beverages that give you gas, bloating, diarrhea, ...
Some things to watch out for include:
dairy
fructose (honey, melons, apples, pears, peaches, some kinds of grapes, juice, dried fruits, canned fruits; that is all fruits EXCEPT fresh berries, bananas, pineapple, kiwis, and citrus)
wheat
gluten
yeast
artificial ingredients or sugars
regular sugar
As for when I first got IBD, my GI uses the date that I got my first flare, that is the first time I saw blood. That flare lasted six months. But it is possible that you had IBD, and not IBS, earlier than you were first diagnosed with UC. Who knows without a scope.
Post Edited (subdued) : 3/6/2011 12:45:55 PM (GMT-7)