Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Celiac Disease Health Center

Font Size

Celiac Disease Diagnosis & Tests

Small intestinal biopsy

People who test positive for celiac disease antibodies, or who have a high probability of celiac disease regardless of the results of the blood tests, should have a small intestinal biopsy to confirm the diagnosis. A small intestinal biopsy is performed with an esophagogastroduodenoscopy (EGD). During an EGD, the doctor inserts a long, flexible viewing endoscope through the mouth and into the duodenum (the first part of the small intestine, which is connected to the stomach). A long, flexible biopsy instrument then can be passed through a small channel in the endoscope to obtain samples of the intestinal lining of the duodenum. A pathologist evaluates the tissue samples for loss of villi and other characteristics of celiac disease, such as an increased number of lymphocytes.

Why is it important to accurately diagnose celiac disease?

Diagnosis of celiac disease should be firmly established before starting a person on a gluten-free diet. Here's why:

  1. The gluten-free diet requires avoiding wheat, barley, and rye -- products that are dietary staples, at least in the U.S.
  2. Patients with irritable bowel syndrome (IBS) may experience improvements in bloating, abdominal pain, and diarrhea with a gluten-free diet. These patients may be misdiagnosed as having celiac disease. Without confirmation of celiac disease by small intestinal biopsy, they may be unnecessarily committed to lifelong gluten restriction.
  3. A gluten-free diet can lower blood antibody levels and allow the microscopic appearance of the small intestine to lose the typical appearance of celiac disease, complicating subsequent efforts at making a firm diagnosis of celiac disease.

How are malabsorption and malnutrition evaluated in celiac disease?

Celiac disease causes malabsorption of nutrients and leads to malnutrition. Tests are available that help in the evaluation of malabsorption and malnutrition; however, because other diseases can cause both malabsorption and malnutrition, these tests cannot be used to diagnose celiac disease.

Stool examination for malabsorption

Stool from patients with celiac disease often contains many globules of fat -- a condition called steatorrhea -- that can be viewed under a microscope using a dye to make them visible. To conclusively diagnose steatorrhea, however, stool is collected over a 72-hour period, and the fat in the stool is chemically measured and quantified.

Because malabsorption and steatorrhea can occur with other intestinal diseases (such as small intestinal bacteria overgrowth, prior small intestinal resection, extensive Crohn's disease of the small intestine, and chronic pancreatitis), stools with large amounts of fat raise the suspicion of celiac disease but cannot be used to diagnose celiac disease.

Today on WebMD

thumbnail for Gluten-free Diet slideshow
Celiac Disease Symptoms
Gluten Intolerance Against Grain
Various vegetables in sautee pan
Expert Q And A Eating With Food Allergies
Celiac Hope
Fresh produce in fridge drawer