Hi Tom -- welcome to the boards.
I personally feel that you need to be realistic without being pessimistic. There are some careers that are probably pretty much impossible if you have IBS, particularly IBS-D -- like being a pilot, for instance. I would not plan your life around the assumption that you will be sick and attack-prone forever -- but I would also not plan your life around the assumption that you'll have gotten all better by the time you've graduated and started working. IBS is a chronic condition with no cure. Could be that you'll manage to keep it in check, but even still you will probably have bad days and you'll need to take that into account. In this respect, what's usually more important is how understanding your employer is rather than the actual job.
And take a good hard look at your "dream". What is it that makes it your dream? We are not necessarily defined by the job we work -- if someone's dream is to become a pilot, he can still take flying lessons and do it for fun even if his IBS won't let him do it full-time as a job. What is it about being a reporter that attracts you? Can you reinterpret your desires into another career or hobby?
Also, depending on what type of reporting you want to do, you may not have to do much travel at all. Sure, if you want to be an international news journalist reporting on the Middle East I would probably tend to shy away from that (I always wonder how anyone can handle having an IBS attack on a squat toilet) -- but if you end up with a job where the travel is more local/regional, that would probably be very do-able for someone with IBS if you're fairly stable.
Anyway, I guess I wouldn't necessarily go, "Yeah, pursue your dream, screw the IBS!" because I don't think that's very sensible. IBS is a medical condition, even if it's one that people tend to dismiss or ignore, and you certainly wouldn't tell someone in a wheelchair that he should go ahead and pursue his dream of becoming a forest ranger. At the same time, you definitely shouldn't let your anxiety rule your life. IBS is usually worsened by anxiety -- so if you focus on getting the anxiety under control, you just may find that your IBS becomes manageable as a consequence.
There are lots of ways to manage anxiety and stress. Lots of people here have done really great with the IBS hypnotherapy sold on this website. Medication is also an option if you don't mind that route -- you can always try increasing your Lexapro if you can't manage your anxiety by other routes.
Good luck, and please do keep posting now that you've "de-lurked".
"It's one of the most serious things that can possibly happen to one in a battle -- to get one's head cut off." -- LC