Stool Specimen Collection

Definition

Stool specimen collection is the process of obtaining a sample of a patient's feces for diagnosic purposes.

Purpose

This procedure is used to test for infectious organisms, mucus, fat, parasites, or blood in the stool.

Precautions

Depending on the proposed analysis of the feces, watery feces will not be suitable for conducting a test for any fat that may be present, but can be used for other analyses, such as testing for bacteria.

Description

A stool specimen or culture can also be called a fecal specimen or culture. A specimen of freshly passed feces of 1/2 to 1 ounce (15 g to 30 g) is collected, without contamination of urine or toilet tissue, into a small container that may have a small spoon or spatula attached inside the lid of the cup for easier collection of the sample.

Adult and older children patient can collect the specimen by passing feces into plastic wrap stretched loosely over the toilet bowl. A portion of the sample is then transferred into the supplied container.

With young children and infants wearing diapers, the diaper should be lined with plastic wrap. A urine bag can be attached to the child to ensure that the stool specimen is not contaminated with urine.

For a bedridden patient, the specimen should be collected in a bedpan lined with plastic wrap, and the nurse can transfer a portion of the feces into the appropriate container.

Follow the manufacturer's guidelines if a commercial collection kit is used.

Preparation

If occult blood is suspected, the patient should be given a mild laxative and should avoid eating foods rich in meat extracts or leafy vegetables three days prior to the test. If the patient's gums bleed when brushing their teeth, the mouth should be cleansed with mouthwash and wiped with a cloth to avoid blood entering the digestive system and contaminating the stool specimen.

Certain drugs may interfere with the analysis of the specimen, and the patient should avoid ingesting products such as antacids, oily foods and drugs, and antibiotics. Barium sulfate should be excluded two weeks prior to the test, and medical procedure dyes three weeks prior to the test.

If fat in the stool is suspected, the patient will also be asked to collect the samples in pre-weighed airtight containers.

All feces passed in a 24-hour period are collected over two or three days and sent daily for analysis.

Aftercare

The patient should be made clean and comfortable.

All contents of kits, towels, plastic wrap, gloves, and bedpans should be disposed of in appropriate containers. The nurse should wash and dry his or her hands thoroughly.

Speed in testing the sample is essential, in order that an accurate result is obtained. Therefore the specimen should be sent for testing as quickly as possible.

Complications

If there is a delay in sending the specimen for testing, organisms present in the feces may die, while others may multiply, giving a false reading.

Patients should inform medical staff of any medications currently being taken as elements of the drugs may be present in the feces.

Results

The specimens are compared with normal values. Abnormal results indicate that infection, disease, or parasite infestation are present.

Health care team roles

The nurse should be aware of the qualities of normal feces, and note if the patient has any difficulties in passing feces. As many patients may feel uncomfortable performing this collection properly, the nurse should also educate the patient concerning the reasons for having it done.

KEY TERMS

Barium sulfate—A water-insoluble salt used as an opaque medium for radiographic contrast.

Occult blood—Hidden blood.

Parasite—An organism that lives on or in another host.

OTHER

"Diagnostic Procedures for Stool Specimens." National Center for Infectious Diseases. <http://www.dpd.cdc.gov> 02/05/01.

"Fecal Culture." <http://www.Webmd.com>.

"Stool for Quantitative Fecal Fat." University of Texas, Houston Medical School. <http://www.Medic.Med.uth.tmc.edu>.

Margaret A Stockley, RGN