How Is Crohn Disease Diagnosed?

Unfortunately, there is no laboratory test that can be used to diagnose Crohn disease. To be certain that you have Crohn disease, you will have to undergo diagnostic imaging studies.

• Barium contrast studies: This is a series of x-rays taken after introduction into your digestive tract of a contrast material containing barium. The barium allows the intestines to show up better than on a plain x-ray. Barium studies are very useful in defining the nature, distribution, and severity of the disease. The barium studies may include an “upper GI series” (x-rays of the upper part of the digestive system), a “small bowel follow-through” (x-rays of the small intestine), and a “lower GI series” (barium enema).
  
  
• CT scan or ultrasound: These scans can be helpful in evaluating complications outside of the intestine, such as fistulas, an abscess, or abnormalities of the liver, bile duct, or kidneys. MRI may be used instead.

• Endoscopy/colonoscopy: This involves inserting a thin tube with a light and a tiny camera on the end into the digestive tract, either through the mouth or the anus. The camera transmits pictures of the inside of the intestine so that the doctor can see inflammation or bleeding or other problems. The doctor may use the instrument to take tiny samples of the inside of the intestinal wall. These samples, or biopsies, are examined under a microscope to see if you have Crohn disease.