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Diagnosing Crohn's

Wireless Capsule Endoscopy. Wireless capsule endoscopy (WCE) is a new imaging approach that is very useful for diagnosing Crohn's disease. With WCE, the patient swallows a capsule containing a tiny camera that records and transmits images as it passes through the gastrointestinal tract. Some studies have found it to be much more accurate for evaluating small bowel disease than barium x-rays or CT scans. Patients also find it easier to tolerate than standard endoscopy.

Ultrasound. Intestinal wall ultrasound is proving to be useful for identifying the extent and severity of Crohn's disease. Although it is unclear if ultrasound is useful for an initial diagnosis, one study indicated that it is effective for identifying Crohn's disease or ulcerative colitis when used by experienced professionals.

Upper and Lower Gastrointestinal Barium X-Rays. An upper gastrointestinal barium x-ray may be used if Crohn's disease is suspected in the small intestine. Swallowed barium passes into the small intestine and shows up on an x-ray image, which may reveal inflammation, ulcers, and other abnormalities.

Computed Tomography (CT) Scans. Computed tomography (CT) scans are proving to be useful in evaluating active IBD. With Crohn's disease, CT scans may show thickened walls and complications, such as fistulas, which occur outside the intestine.

Magnetic Resonance Imaging (MRI). Magnetic resonance imaging is another advanced imaging technique that may be useful for detecting abscesses and other injuries related to Crohn's disease in the pelvis. A variant called magnetic resonance spectroscopy (MRS) may prove to be useful for differentiating between Crohn's disease and ulcerative colitis.

Using Tests to Differentiate Between Crohn's Disease and Ulcerative Colitis
Endoscopy	Ulcerative colitis almost always involves the lower left colon and rectum and can be diagnosed using sigmoidoscopy. Crohn's disease may require colonoscopy as well. Endoscopy often reveals ulcers, diseased regions that have a cobblestone-like appearance in Crohn's disease, but not in ulcerative colitis.
X-Rays (Barium Enema) or Computed Tomography Scans	In ulcerative colitis, inflammation is usually evenly distributed on the surface lining of the intestine, and the bowel wall bleeds easily when touched with a swab. The pattern observed in Crohn's disease is usually one of scattered patches of ulcers that are deep, thick, and large. Crohn's disease produces pockets (fissures) or channels (fistulas). They do not occur with UC. In ulcerative colitis the ileum (the lower part of the small intestine) is often dilated while it is narrowed in Crohn's disease.
Laboratory Tests	Tissue samples obtained from a patient with Crohn's disease may reveal granulomas, small collections of inflammatory cells. Granulomas may also be present in other conditions, however. Tissue samples should also be examined for the presence of cancerous cells. In tests for antibodies, about 70% of tests for patients with UC will show immune factors called perinuclear-staining antineutrophil cytoplasmic antibodies, and over 50% of Crohn's patients have anti-Saccharomyces cerevisiae antibodies. Each of these antibody groups shows up only occasionally in the other disorder.