MedlinePlus Medical Encyclopedia: Culture

Skip navigation


Medical Encyclopedia
Other encyclopedia topics:	A-Ag Ah-Ap Aq-Az B-Bk Bl-Bz C-Cg Ch-Co Cp-Cz D-Di Dj-Dz E-Ep Eq-Ez F G H-Hf Hg-Hz I-In Io-Iz J K L-Ln Lo-Lz M-Mf Mg-Mz N O P-Pl Pm-Pz Q R S-Sh Si-Sp Sq-Sz T-Tn To-Tz U V W X Y Z 0-9

Culture - colonic tissue biopsy

Contents of this page:
Illustrations Alternative names Definition How the test is performed How to prepare for the test How the test will feel	Why the test is performed Normal Values What abnormal results mean What the risks are Special considerations

Illustrations

Colonoscopy

Colon culture

Alternative names Return to top

Colonic tissue culture

Definition Return to top

A colonic tissue culture is a laboratory test performed on a specimen of colon (large intestine) tissue to isolate and identify organisms that may be causing certain infections, such as infectious diarrhea or parasitic and viral infections involving the colon.

The specimen is obtained by a colonoscopy. A colonoscopy is a procedure for viewing the interior lining of the colon using a colonoscope, a flexible fiber-optic tube about 1/2 inch thick.

How the test is performed Return to top

A sample of colon tissue is obtained during a colonoscopy procedure using special instruments. The specimen is sent to the laboratory and placed in special culture media. The specimen is incubated at different temperatures and examined daily for the presence of microorganisms.

If certain microorganisms are detected, the laboratory will perform additional testing to further classify them. Susceptibility testing of the microorganisms will help find the best antimicrobial therapy.

How to prepare for the test Return to top

The preparation for the culture is the same as for a colonoscopy. The large intestine must be thoroughly cleansed. You may be asked to take laxatives or an enema the evening prior to the test. You will likely be instructed to be on a clear liquid diet for 24 to 48 hours before the test.

Before the colonoscopy is performed, the risks and benefits of the procedure will be explained to you, and you will be asked to sign a consent form. You may be given a sedative to help you relax as the colonoscopy is being done.

Infants and children:
The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

Infant test or procedure preparation (birth to 1 year)
Toddler test or procedure preparation (1 to 3 years)
Preschooler test or procedure preparation (3 to 6 years)
Schoolage test or procedure preparation (6 to 12 years)
Adolescent test or procedure preparation (12 to 18 years)

How the test will feel Return to top

You may feel the urge to defecate when the colonoscope is inserted.

Why the test is performed Return to top

The culture is performed to detect and identify certain infections which can affect the colon, especially when other tests such as stool culture have been unable to identify the underlying infection.

A colonoscopy may also be performed for other reasons, such as to identify certain forms of cancer or inflammatory bowel disease.

Normal Values Return to top

The colon has a high number of well-characterized bacteria termed "bowel flora." The growth of these organisms in culture from a colonic biopsy does not mean there is an infection. These organisms are part of the normal flora present in the gut.

What abnormal results mean Return to top

The detection of certain organisms in a colonic biopsy culture is considered abnormal. This includes certain bacteria, such as salmonella, shigella, Clostridium difficile, Mycobacterium tuberculosis and others. Parasites such as schistosomiasis and viruses such as cytomegalovirus are other examples of pathogenic organisms that may be detected.

What the risks are Return to top

A colonoscopy is usually a safe procedure. However, it can cause a perforation (hole) in the large intestine, infection, and bleeding.

Special considerations Return to top

After the colonoscopy, you may have large amounts of flatulence (gas) caused by the air used to distend the colon.

Update Date: 1/26/2004

Updated by: Daniel Levy, M.D., Ph.D., Infectious Diseases, Greater Baltimore Medical Center, Baltimore, MD. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.