My husband has Crohn's Disease, symptomatic since 1991, but not diagnosed till 2000. For him, he had a series of peri-anal abscesses that were treated as one-off events by student health services during the decade he was in grad school. But, everything came to a head in 2000 when he developed a mass in his small intestine. He was cramping, bloated, and having urgent loose stools all the time. They finally imaged the mass with a barium swallow, but they didn't actually diagnose Crohn's until after they resected several feet of his intestines and sent it down to the pathology lab.
One new, less invasive way of diagosing Crohn's (and other diseases of the small bowel) is the Given PillCam SB. It's a little capsule you swallow with a camera in it (about the size of a large prenatal vitamin). You wear a belt pack around your waist for the day and that data is downloaded to the GI's computer. Based on those images, the doctor can figure out what's going on. It's a pretty patient-friendly way to image the small intestine.
Fortunately, my husband has got a moderate case and it's kept under control with Imuran (an immunosuppressant approved for pediatric leukemia, but it often works very well for Crohn's patients).
If you can get there, the U of C GI department is one of the best in the nation. Dr. David Rubin is wonderful. Dr. Stephen Hanauer is one of the leading researchers on Crohn's, but I'd say his bedside manner leaves something to be desired.
If you're up on the north shore, I'd suggest checking with Dr. Eli Erhenpreis with the North Shore Medical Group. He used to be at the U of C, and is an excellent clinician.
Good luck!
D.