Give her some time.
I'm a teenager with epilepsy, which is has been in remission (at the least) for the past four years. I was first diagnosed eight years ago, at the age of ten. Things were difficult to deal with for a while, but I had the support of my friends. The worst part was knowing that symptoms could manifest themselves without much warning, and while medication strongly lessened them, and prevented full-blown tonic-clonic seizures, I knew that I needed to trust my friends and family to do the right thing on the off chance that something terrible happened.
My first (and current) relationship started about a year after I had my last major seizure. I didn't know whether my epilepsy would continue to progress, and it still worried me. I went on a date or two with my girlfriend, and eventually told her about my condition and the history behind it. I did a couple things in particular:
- I explained what the disease is and, in general, how it works.
- I told her about my experiences with it, and my current status.
- I was up front about what could happen in the future, and what I would need help with.
- I told her about what things I can't do because of epilepsy and the medication I take (for instance, I can't drink and avoid strobe lights and clubs).
There's a very realistic possibility that the two of us could be alone and I could have a seizure of some sort. She would be the one to get help, and I would have to trust that she would do the right thing. I don't think she was overly bothered by it, but it did take a bit of time for her to understand what things I can and can't do.
What she might be thinking
We can't know for sure (yet) what in particular is bothering the person you're dating. I do have some ideas:
- If it's the risk of something terrible happening to you, reassure her that your condition is not fatal. While you'll have many things to deal with in your life, this is not a disease that is going to seriously disrupt your life to the extent that something like cancer might. You've been strong so far, and you're going to get through this.
- If it's the reluctance to shoulder the responsibility to help you if something goes wrong, be clearer on what (if anything) she would have to do. It does seem like you've done a good job of that.
- If it's any possible lifestyle limitations that you might have, maybe this isn't the relationship for you. In my case, I simply wouldn't have been able to date someone who couldn't accommodate my medical needs. If my girlfriend wanted to always stay out late, or drink, or whatever, then I simply couldn't have continued. Relationships need to be healthy for all parties involved.
What to do right now
Consider that what you've told her may be a bit of a surprise. I wouldn't blame her for not quickly agreeing to continue dating. Your condition, as I said, requires trust, and agreeing to that trust, is not something to be done likely. I don't think she's done anything wrong by taking some time to think it over.
I can't say that I'm that familiar with IBD, but it's certainly not something to be taken lightly by her. My girlfriend was pretty understanding about my epilepsy, but it took some time for things to fully sink in. I wouldn't have wanted to rush her in any way, and I think that you're doing the right thing by letting her think.
You do need to let her know that you (hopefully) understand her reluctance. You haven't rushed her; that's great. However, given that it seems to be the next day, you should acknowledge what you told her and reassure her that you support her taking the time to think about it. You could call her or send an email (or a text, but texts are, in my humble opinion, a bit short and casual for matters like this).
I'm not having an easy time remembering exactly what I told my girlfriend when I said something similar, but it was along these lines:
I know that what I told you might be a bit of a surprise. I understand that you might be a bit reluctant about things. At first, epilepsy was hard for me to deal with, but over time, it's gotten better. I really don't want to rush you into making a decision yet, and I hope that you understand what the situation is like for me. Let me you if you want to talk more about it.
The conversation that followed was actually pretty short, because she adjusted well to the problem, but I would not assume that the same will be true in your case.