Rectal culture is a laboratory test to isolate and identify organisms in the rectum that can cause gastrointestinal symptoms and disease. Normally, many organisms are present in the lower gastrointestinal (GI) tract, but some can act as pathogens (disease-causing organisms) in the bowel.
How the test is performed
A cotton swab is inserted into the rectum, rotated gently, and withdrawn. A smear of the swab is placed in culture media to encourage the growth of microorganisms. The culture is observed for growth at regular intervals in the laboratory. When growth is observed, the organisms can be identified. Further tests to determine sensitivity of the organisms to antimicrobial therapy may also be carried out (see sensitivity analysis).
How to prepare for the test
A rectal examination is done by the health care provider.
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)
- School age test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
There may be pressure as the swab is inserted into the rectum, but the test is usually not painful.
Why the test is performed
The test is performed when gastrointestinal distress is present and infection is suspected as a cause of the distress. It may be performed when a gonorrhea infection is suspected. It may be performed as an alternative to a fecal culture if it is not possible to obtain a feces specimen.
It may also be performed in a hospital or nursing home setting to see if someone carries vancomycin-resistant enterococcus (VRE) in their intestine, which can be spread to other patients. Patients with VRE are often maintained on isolation precautions.
The presence of organisms that are usually found in the body is normal.
What abnormal results mean
Abnormal results may indicate an infection, such as bacterial or parasitic enterocolitis or gonorrhea. Sometimes culture shows the presence of vancomycin-resistant enterococcus, which means the patient is a carrier, but does not necessarily have an infection.
What the risks are
There are no risks.
by Brenda A. Kuper, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.