I am new here and felt really compelled to respond to your post. I am so sorry that this past year has been so difficult for you. I fortunately did not have crohn's while I was in college however I was a single teenage mother. I understand how hard it can be to juggle what life throws at you while trying to attend college. I do not know how much advocating you have done for yourself. Have you met with your professor for the class you received the C- in? Have you met with your acedmic advisor for your major? Believe me nothing is ever written in stone. There is always a loop hole to make things better. The college wants you to as well as you can because it ultimately looks good for them. Speak with the professor from the class you recived the C- in. They may be willing to give you an extra paper to write to bring your grade up to a C. Most colleges will make exceptions for their students who have extenuating circumstances you just need to ask. Bring your medical records to meet with your advisor and have whom ever you can get write you letters of support. If you need to play a chelo rather than a violin to plead your case, do so. There is no shame in it, this is your acedmic future you are talking about. I know all about the playing the chelo :) Good Luck!!
Sorry to hear about troubles with school.
I would certainly mention your medical condition to your professors, but a professor may not be able to do too much to accommodate you. A better tack will be to seek out student support services, which should be able to document your medical condition and limitations and then you can present this documentation to your professors.
Although meeting with a student retention specialist probably won't hurt, you should make sure this person understands that your problem isn't one of academic preparedness and is medical in nature.
Too, if I'm not mistaken, you should be able to swing a one-time exemption on financial aid.