Celiac disease affects the digestive system, leading to various symptoms and health concerns. This information can help clarify which tests are appropriate for detecting celiac disease.
Understanding Celiac Disease
Celiac disease is an autoimmune disorder primarily impacting the small intestine. When individuals with this condition consume gluten, a protein found in wheat, barley, and rye, their immune system responds unusually. This response leads to damage in the lining of the small intestine.
The small intestine’s inner surface is covered with tiny, finger-like projections called villi. These villi play a role in absorbing nutrients from food. In celiac disease, the immune reaction to gluten causes these villi to flatten and become damaged, hindering the body’s ability to absorb nutrients.
This damage can result in nutritional deficiencies and a range of symptoms, which can vary among individuals. Celiac disease is hereditary and can develop at any age after gluten consumption begins.
The Scope of a Colonoscopy
A colonoscopy is a medical procedure designed to examine the inside of the large intestine. A long, flexible tube equipped with a camera, known as a colonoscope, is inserted through the anus to visualize these areas. This procedure is used to screen for conditions such as colon cancer and to investigate symptoms related to the lower digestive tract, like rectal bleeding or changes in bowel habits.
While a colonoscopy provides a detailed view of the large bowel, it often reaches the end of the small intestine, specifically the terminal ileum. However, it does not thoroughly examine the duodenum. Damage from celiac disease predominantly occurs in the duodenum, making a colonoscopy less suitable for identifying this condition.
Diagnosing Celiac Disease
A colonoscopy is not the primary method for diagnosing celiac disease. The characteristic damage to the small intestine in celiac disease, particularly villous atrophy, primarily affects the duodenum. The colonoscope does not usually reach this upper part of the small intestine where the most changes occur.
The diagnostic pathway for celiac disease typically begins with specific blood tests. These tests look for antibodies produced in response to gluten. Common antibody tests include tissue transglutaminase IgA (tTG-IgA) and endomysial antibody (EMA) tests. A total IgA level is also measured to ensure accurate interpretation of these results.
If blood tests indicate the possibility of celiac disease, the next step usually involves an upper endoscopy. During this procedure, a flexible tube with a camera is passed down the throat, through the esophagus and stomach, and into the duodenum. This allows a gastroenterologist to visually inspect the duodenal lining and collect biopsies.
These biopsies are then examined under a microscope for signs of villous atrophy and other changes consistent with celiac disease. Individuals must continue consuming gluten in their diet before these tests are performed, as avoiding gluten can lead to inaccurate or false negative results, making diagnosis difficult. A definitive diagnosis relies on both positive blood test results and histological evidence from duodenal biopsies.