Understanding Crohn’s Testing

Samples of stool may be tested for pathogenic bacteria and certain markers of inflammation. Your doctor will give you a container for collecting and storing the stool.

This diagnostic test allows your doctor to evaluate your intestine by tracking the movement of a thick, chalky liquid called barium. The barium dye coats the lining of the bowel—creating a silhouette of your rectum, colon, and a portion of your intestine that’s visible on an X-ray. For contrast X-rays of the small intestine, you will be asked to drink the barium, and for the large intestine barium will be inserted into the rectum. Because of the availability of more advanced tests, like colonoscopy and computerized tomography (CT) scanning, contrast X-rays aren’t typically used anymore.

A CT scan takes simultaneous X-rays from different angles to create a cross-sectional image of the bowel—as well as images of tissues outside the bowel that can’t be seen with other tests. CT scans help your doctor diagnose your Crohn’s and determine the location and extent of your disease. They can also help check for potential complications and rule out conditions with similar symptoms.

White blood cells are drawn to the site of inflammation in the body. This test tracks your white blood cells to determine how much inflammation your Crohn’s may be causing in your gastrointestinal (GI) tract.

This test uses a thin, flexible tube with a lighted camera inside the tip (called an endoscope) that allows your doctor to explore different parts of your gastrointestinal (GI) tract. This technique includes tests like:

• Sigmoidoscopy: Examines the sigmoid, the lower third of your large intestine (the rectum and the sigmoid colon).
• Colonoscopy: Provides a view of your entire colon and helps your doctor determine whether you have Crohn’s disease or ulcerative colitis (UC).
• Capsule Endoscopy: This uses a capsule containing a tiny video camera, an LED light, a radio transmitter, and a battery. You swallow the capsule, and as it travels through your intestines, the camera captures images which are transmitted to a computer. Your doctor views the images to check for signs of Crohn's disease. The capsule is passed painlessly in stool. There is now an improved version that dissolves 2 to 4 days after being swallowed.
• Esophagogastroduodenoscopy (EGD): Also referred to as upper GI endoscopy, it examines 3 areas that can be affected by Crohn’s disease: the esophagus, the stomach, and the duodenum (the first part of the small intestine).
• Endoscopic Retrograde Cholangiopancreatography (ERCP): This procedure combines upper GI endoscopy and X-rays to examine bile ducts in the liver and pancreatic ducts—which may be affected in some people with Crohn's.
• Double Balloon Endoscopy (DBE): A longer scope with 2 inflatable balloons attached used to explore areas throughout the entire small intestine.

An endoscopy may be combined with ultrasound. An ultrasound probe is attached to the endoscope to create specialized images of the wall of your esophagus or stomach—or to create images of hard-to-reach organs, such as your pancreas. Newer endoscopes use high-definition video to provide very clear images.

A large magnet and radio waves help doctors look at organs and structures inside your body. MRI is very helpful in diagnosing and managing Crohn's.

• Pelvic MRI: Commonly used for evaluating fistulas around the anal area.
• MRI Enterography: Commonly used for examining the small intestine.