How Do You Test for IBD (Inflammatory Bowel Disease)?

Ask a Doctor

I’ve been having intestinal pain and diarrhea for the last week, but I don’t have any other symptoms of gastroenteritis or stomach flu. I’m worried I might have inflammatory bowel disease. How is IBD diagnosed? How do you test for IBD?

Doctor's Response

A health care professional makes the diagnosis of inflammatory bowel disease based on the patient's symptoms and various diagnostic procedures and tests.

Stool Examination

  • A stool examination is done to eliminate the possibility of bacterial, viral, or parasitic causes of diarrhea.
  • A fecal occult blood test is used to examine stool for traces of blood that cannot be seen with the naked eye.

Complete Blood Count

Both the above tests are not diagnostic of IBD, as they may be abnormal in many other diseases.

Barium X-Ray

  • Upper gastrointestinal (GI) tract: This exam uses X-rays to find abnormalities in the upper GI tract (esophagus, stomach, duodenum, sometimes the small intestine). For this test, you swallow barium (a chalky white substance), which coats the inside of the intestinal tract, and can be documented on X-rays. If a person has Crohn's disease, abnormalities will be seen on barium X-rays.
  • Lower gastrointestinal (GI) tract: In this exam, barium is given as an enema that is retained in the colon while X-rays are taken. Abnormalities will be noted in the rectum and colon in persons with Crohn's disease and ulcerative colitis.
  • Sigmoidoscopy
  • In this procedure, a doctor uses a sigmoidoscope (a narrow, flexible tube with a lens and a light source) to visualize the last one-third of the large intestine, which includes the rectum and the sigmoid colon. The sigmoidoscope is inserted through the anus and the intestinal wall is examined for ulcers, inflammation, and bleeding. During this procedure, the doctor may take samples (biopsies) of the lining of the intestine.


A colonoscopy is an examination similar to a sigmoidoscopy, but with this procedure, the entire colon can be examined.

Upper Endoscopy

If you have upper GI symptoms (nausea, vomiting), an endoscope (narrow, flexible tube with a light source) is used to examine the esophagus, stomach, and the duodenum. The endoscope is inserted through the mouth, and the stomach and duodenum are examined for ulceration. Ulceration occurs in the stomach and duodenum in 5% to 10% of persons with Crohn's disease.

Health Solutions From Our Sponsors

Crohn's & Colitis Foundation of America. "IBS and IBD: Two Very Different Disorders." Published June 1, 2012.

Crohn's & Colitis Foundation of America. "What are Crohn's & Colitis?

Farrell, R.J., MD., et al. "Overview of the medical management of mild to moderate Crohn disease in adults." UpToDate. Updated: Jul 28, 2016.

Rowe, W.A., MD. "Inflammatory Bowel Disease." Medscape. Updated: Jun 17, 2016.

Peppercorn, M.A., MD., et al. "Definition, epidemiology, and risk factors in inflammatory bowel disease." UpToDate. Updated: Nov 08, 2016.