A colonic tissue culture is a lab test to check for the cause of disease. The sample of tissue for the test is taken from the large intestine during a sigmoidoscopy or colonoscopy.
How the Test is Performed
The health care provider removes a piece of tissue from your large intestine. This is done during a colonoscopy.
- The sample is sent to a lab.
- It is placed in a special dish that contains a gel. Bacteria and other organisms can grow in this gel. The dish is then stored at a certain temperature.
- The lab team checks the sample daily. They check to see if bacteria, viruses, or fungi have grown.
If certain germs grow, more tests will be done to identify them. This helps decide the best treatment.
How to Prepare for the Test
There is no specific preparation needed for a culture. In some cases, the provider performing the exam may recommend using an enema before the exam.
How the Test will Feel
Once the sample is taken, the culture does not involve you. Therefore, there is no pain.
Why the Test is Performed
Your provider may order this test if you have signs or symptoms of a large intestine infection. A culture is often done when other tests, such as a stool culture, could not identify the cause of infection.
A normal result means that no disease-causing organisms have grown in the lab dish.
Some "healthy" bacteria, called bowel flora, are normally found in the gut. The growth of such bacteria during this test does not mean there is an infection.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about your test results.
What Abnormal Results Mean
There is very minimal risk associated with the procedure. In rare cases, excessive bleeding could occur when a tissue sample is taken.
Colonic tissue culture
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Review Date 4/10/2020
Updated by: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.