work and crohn's

that is a difficult one- i developed crohn's 2 years ago while working in a very busy ER as a nurse practitioner. I was recently terminated after 2 episodes of bad health/luck. First i contracted a staph infection which left me hospitalized for 5 days, and then 5 months later, I had a reaction to remicade and could not walk for 2 days. they said i was being let go because it was not "a good fit", but  I was doing very well professionally with the exception of the 2 times i mentioned. I think that they saw the potential for disability down the road and got out while they could. They gave me a fairly good severance package, but it was still a slimy thing to do. I now work in an urgent care clinic, and did not tell anyone before i was hired, as it did not affect my ability to do my job. Now that I am on board, I have let it be known to certain individuals so that they understand why I need to lay down for my lunch break instead of goingout for pizza, or why I try and space the days that I work so i do not get so tired.

It is against the law, but that's all the more reason for them NOT to cite illness as a reason for termination. There are plenty of other reasons they can put down on paper.
Is there any way that you might still be able to contact the disability services office from your university? Mine had an extremely helpful staff that spoke with me for at least a full hour on all your options concerning job interviews, being hired, when/if you disclose your disability, etc.
As for any answer I can give from my own experiences, choosing to tell your boss about your illness is up to your own personal judgment. You may need to in order to request certain accommodations keeping in mind that not all of them are reasonable and that many companies have the right not to hire you based on accommodations you may HAVE to have.
I think in the end you just have to kind of gauge how things will go, find the right boss(there are many who are very understanding while some are the complete opposite), and try to make sure you're in an environment that doesn't make you miserable.
I know it's all easier said than done, but I have faith that you can do it :)
You'll always have support here. I'm also sure there will be a lot many, much more helpful, answers coming along from the other members.

That just sucks!!! I've been fortunate that I have been at my place of work for over 20 years and they are understanding of my disease.

It may be against the law to fire someone because of a disease, but the bigger question here is whether they'll fail to hire because of a disease. That's illegal, too, but the hiring process is even less transparent than firing.

Small companies won't want to take on someone with a large insurance burden, unless they're a small, flexible, wildly profitable company. Larger companies- thousands of employees- don't care quite so much because it all comes out in the wash, statistically. Universities and state/federal employment may be best for particularly financially debilitating disorders.

None of this means you should necessarily disclose your illness to any HR reps. They may not understand completely. It is something that, if offered the job, you should discuss with whomever will be your immediate supervisor and determine whether the position is right for you. Most importantly, it should be made clear that stress does not seem to be correlated with flares (depending upon who you ask), and that it is possible to control the disease for months or years at a time.

Lastly, it is worth noting to potential employers that, yes- you do have a nasty disease but dealing with chronic pain and discomfort makes for a tougher employee. By and large, Crohnies aren't the kind of person to call in sick because of a hangnail or a touch of tummy upset.