Stool gram stain

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Overview

Risks

Results

Stool gram stain

Definition:

Gram stain is a method of identifyng microorganisms (bacteria) using a special series of stains. In this test, a specimen of stool is stained and then examined under the microscope.

The Gram stain method can be applied to almost any clinical specimen and is one of the most commonly used techniques for the rapid diagnosis of bacterial infections.

Alternative Names:

Gram stain of stool; Feces Gram stain

How the test is performed:

A small amount of stool is applied in a very thin layer to a microscope slide. This is called a smear. A series of stains called a Gram stain is applied to the specimen. It is first stained with crystal violet stain, then iodine, then decolorized, then stained with safranin.

The stained smear is then examined under the microscope for the presence of bacteria. The color, size, and morphologic appearance (shape) of the cells help identify the infecting organism.

How to prepare for the test:

For adults and children:

There are many ways to collect the samples. You can catch the stool on plastic wrap that is loosely placed over the toilet bowl and held in place by the toilet seat. Then, put the sample in a clean container. One test kit supplies a special toilet tissue that you use to collect the sample, then put the sample in a clean container.

For infants and young children in diapers:

Line the diaper with plastic wrap. If the plastic wrap is positioned properly, isolating the stool from any urine output, mixing of urine and stool can be prevented for a better sample.

How the test will feel:

Some people feel discomfort or embarrassment with this test.

Why the test is performed:

The test may be performed to try to diagnose an infection or illness, sometimes involving diarrhea.

Review Date: 2/10/2006
Reviewed By: Kenneth Wener, M.D., Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA. 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 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.