Stool Gram stain

Gram stain of stool; Feces Gram stain

A stool Gram stain is a laboratory test that uses different chemical stains to detect and identify bacteria in a stool sample.

The Gram stain method is sometimes used to quickly diagnose bacterial infections.

Gram stain

A Gram stain is a test used to help identify bacteria. The tested sample can be taken from body fluids that do not normally contain bacteria, such as blood, urine, or cerebrospinal fluid. A sample can also be taken from the site of a suspected infection, such as the throat, lungs, genitals, or skin. Bacteria are classified as either Gram-positive or Gram-negative, based on how they color in reaction with the Gram stain. The Gram stain is colored purple. When combined with the bacteria in a sample, the stain will either stay purple inside the bacteria (Gram-positive), or it will turn pink (Gram-negative). Examples of Gram-positive bacteria include Streptococcus and Staphylococcus aureus, as well as bacteria that cause anthrax, diphtheria, and toxic shock syndrome. Examples of Gram-negative bacteria include Escherichia coli (E coli), Salmonella, Hemophilus influenzae, as well as many bacteria that cause urinary tract infections, pneumonia, or peritonitis.

How the Test is Performed

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean

Risks