I was diagnosed w/ Ulcerative Colitis late in 2001.
I used to train and fight w/ Tommy Bottone. I stopped because a busy work and home schedule didnt allow me time to train. However, even if i wanted to, i probably wouldnt have been able to anyway.

When i first got it, it started w/ severe stomach pains and extreme bloating. So much bloating that my stomach was swollen and it hurt to walk. That was followed by frequent trips to the bathroom and blood in the bowl.
I went to a doctor who prescribed asacol. i was taking 3 pill 3 times a day (9 totatl) which did almost nothing. I did this for 1 1/2 years. I seemed to aleaviate the pain and bloating a bit, but the frequent bathroom trips and blood continued daily. I eventualy stopped taking the medicine because in addition to doing almost nothing, my hair began thinning (one of the side effects)

I did a lot of research on my own to try and correct it through natural means.
Its funny because most sites i went to said something a little different. One site I found made perfect sense to me. I found that it usually develops following a bad stomach virus. It kills of certain enzymes in your stomach that are supposed to exist to help break down food. Then when you eat certain foods, your body cant break them down correctly. Especially high carbohydrate foods. Foods high in carbohydrates produce yeast which your body can no longer break down properly. Because of its inability to break it down correctly, it sees it as a virus and starts to attach it. This leads to pain, inflamation, blood, etc... So the site suggested an all protein diet to eliminate carbs and the production of yeast in the stomach. ANYWAY, I tried it the best I could and that didn't help.

I began look at supplements. I found that glutamine was also supposed to help.
This article is from http://www.bodybuilding.com/fun/vm8.htm
"How Does It Work?

Skeletal muscle is a major player in the release of glutamine during times of need. It has even been hypothesized that skeletal muscle releases the majority of glutamine into plasma when required by other tissues (Rowbottom, 1996). However, during these times of extreme need, as in the case with the overtraining syndrome (OTS) and intense exercise, more glutamine is required than the body is able to produce. This is why glutamine has been declared a "conditionally" essential amino acid.

It is during these times that it is necessary to supplement because the body cannot synthesize enough to meet demands. Glutamine supplementation is also used in patients suffering from gastrointestinal disorders such as Crohn's disease, irritable bowel syndrome (IBS) and peptic ulcers because the lining of the gastrointestinal tract has the highest turnover of cell production and preferentially uses glutamine stores. It is also used for the treatment of AIDS, cancer, burn victims, autoimmune diseases, fibrosis, stress, fatigue, and alcoholism. It has also been suggested that glutamine stimulates the release of growth hormone (Welbourne, 1995). "

ANYWAY, that didn't work either.

So, I went to another doctor. She prescribed 'Pentasa'. Well this finally worked. It worked almost instantly. No pain, no bloating, normal trips to the bathroom, no more blood, and my hair has grown back.
I've been taking it about 8 months and it works great.
So, in my experience, diet had no effect, Supplements had no effect, and in some cases even medicine had no effect. So, what i would suggest is try one medicine, if that doesn't work after a few months try another. If your doctor wont give you another, try a new doctor.
Good Luck