Inflammatory Bowel Disease

Diagnosis

Mayo Clinic doctors are likely to use a combination of blood tests, endoscopic exams, X-rays and tissue tests to diagnose IBD. Over time, you may need additional tests to monitor your condition and to watch for complications and side effects of medications.

Endoscopy

Among the first steps in diagnosis at Mayo Clinic is a visual examination of the colon using a thin, flexible tube with a lighted camera at the tip. Magnified images of the colon are projected to a television screen. Two types of endoscope exams are commonly used:

• A sigmoidoscopy examines the lower third of your large intestine (sigmoid colon).
• A colonoscopy examines your entire colon, sometimes including the very end of the small intestine (ileum).

During endoscopic procedures, doctors usually remove one or more small tissue samples for examination in the laboratory. This is important for distinguishing different forms of IBD and for diagnosing microscopic colitis, which can only be detected under a microscope.

Capsule endoscopy

Mayo Clinic doctors also use capsule endoscopy, a noninvasive procedure for evaluating the small intestine. You swallow a pill-sized device which takes pictures as it travels through your digestive tract. Because capsule endoscopy views the entire 30-foot length of the small intestine, it can help find problems beyond the reach of traditional endoscopic procedures. The clarity of the images may also help detect problems missed by other diagnostic methods.

Radiology tests

Doctors at Mayo Clinic frequently use two novel, noninvasive imaging techniques to view the entire bowel wall and small intestine. Noninvasive imaging has proven far more effective than traditional barium studies in detecting Crohn's disease, in particular.

• Multiphase CT enterography uses very fast CT scanning and a contrast dye to obtain detailed cross-sectional images of the abdomen. Unlike a conventional CT scan, CT enterography provides a clear view of the small intestine.
• MR enterography (MRE) uses a magnetic field and radio waves rather than radiation to create high-contrast images of the small intestine as well as to locate problems outside the bowel. Because MRE doesn't use X-rays, it is especially helpful to track Crohn's disease in younger people, who might otherwise receive high amounts of radiation over a lifetime.