Fecal occult blood testing (FOBT) may be used to detect occult blood in the stool. It is used for initial/early screening for disorders such as cancer and for gastrointestinal (GI) bleeding in conditions such as ulcer disease, inflammatory bowel disorders, and intestinal polyps (MedlinePlus, 2020). Consecutive stool samples (three to six) should be collected from different stool samples to increase accuracy (Fischbach et al., 2022). FOBT may be performed within an institution, collected at the bedside, and sent to the laboratory for analysis. It may also be collected by the patient at home and delivered or mailed to the health care provider's office or to the laboratory for analysis.

The guaiac fecal occult blood test (gFOBT) is a chemical test that detects the enzyme peroxidase in hemoglobin molecules when blood is present in the stool sample. A positive gFOBT result indicates that abnormal bleeding is occurring somewhere in the digestive tract. Certain medications, such as a salicylate intake of more than 325 mg daily, other nonsteroidal anti-inflammatory drugs, steroids, iron preparations, and anticoagulants, also may lead to false-positive readings (Fischbach et al., 2022). The evidence for practice is conflicting regarding the impact of ingestion of certain foods and supplements before specimen collection on the accuracy of the test results (Doubeni, 2021; MedlinePlus, 2021). Foods and supplements that are suggested to have a possible effect on test results include red meat, cantaloupe, turnips, radishes, parsnips, horseradish, mushrooms, broccoli, cauliflower, apples, bananas, cantaloupe, and vitamin C-enriched foods and juices as well as vitamin C in excess of 250 mg/day (American Cancer Society, 2020; Colorectal Cancer Alliance, 2019a; Fischbach et al., 2022; MedlinePlus, 2021). Patients should consult with their health care providers and follow directions provided for the collection test kit provided.

The fecal immunochemical test (FIT) uses antibodies directed against human hemoglobin to detect blood in the stool. A positive FIT is more specific for bleeding in the lower GI tract (Fischbach et al., 2022). No drug or dietary restrictions are required for the FIT (American Cancer Society, 2020; Colorectal Cancer Alliance, 2019b).

The following are recommendations for the patient preparing for a fecal occult blood test (Fischbach et al., 2022):

• Avoid barium enemas for 72 hours before and during stool specimen collection.
• Do not collect samples during or until 3 days after a menstrual period.
• Do not collect samples while the patient has bleeding hemorrhoids or hematuria.

In clinical settings, these restrictions are usually not practical. Be sure to note the presence of any of the previously mentioned conditions in the clinical setting.

A positive result from either the gFOBT or the FIT requires follow-up testing, such as a sigmoidoscopy or colonoscopy (American Cancer Society, 2020).

Assessment

Assess the patient's understanding of the collection procedure and their ability to engage in their care. Assess the patient for a history of GI bleeding. Review prescribed restrictions for medications and evaluate patient engagement with the required restrictions. Assess the patient for any blood in the perineal area, including hemorrhoids, menstruation, urinary tract infection, or vaginal or rectal tears. Blood may be from a source other than the GI tract.

Actual or Potential Health Problems and Needs

Many actual or potential health problems or issues may require the use of this skill as part of related interventions. An appropriate health problem or issue may include:

• Knowledge deficiency
• Anxiety

Outcome Identification and Planning

The expected outcomes to achieve are that an uncontaminated stool sample is obtained following collection guidelines, and it is then transported to the laboratory within the recommended time frame. Other outcomes may include that the patient demonstrates accurate understanding of testing instructions and rationale for use.

Implementation

Action	Rationale
1. Verify the prescribed intervention for a stool specimen collection in the patient's health record. Gather equipment.	Verifying the prescribed intervention is crucial for ensuring that the proper procedure is administered to the right patient. Assembling equipment provides for an organized approach to the task.
2. Perform hand hygiene and put on PPE, if indicated.	Hand hygiene and PPE prevent the transmission of microorganisms. PPE is required based on transmission precautions.
3. Identify the patient.	Identifying the patient ensures the right patient receives the intervention and helps prevent errors.
4. Discuss with the patient the need for a stool sample. Explain the process by which the stool will be collected, either from a bedpan, commode, or plastic receptacle in the toilet.	Discussion and explanation help to allay some of the patient's anxiety and prepare them for what to expect.
5. If sending the specimen to the laboratory, check the specimen label with the patient identification bracelet. The label should include the patient's name and identification number, the time the specimen was collected, the route of collection, identification of the person obtaining the sample, and any other information required by facility policy.	Facilities may allow point-of-service testing (at the bedside or on unit), or the specimen may have to be sent to the laboratory for testing. Confirmation of patient identification information ensures the specimen is labeled correctly for the right patient.
6. Assemble equipment on the overbed table or other surface within reach.	Arranging items nearby is convenient, saves time, and avoids unnecessary stretching and twisting of muscles on the part of the nurse.
7. Close the curtains around the bed or close the door to the room, if possible.	Closing the door or curtain provides for patient privacy.
8. Place the plastic collection receptacle in the toilet, if applicable. Assist the patient to the bathroom, onto the bedside commode, or onto the bedpan. Instruct the patient not to urinate or discard toilet paper with the stool.	Proper collection into an appropriate receptacle for stool prevents inaccurate results. Urine or toilet paper can contaminate the specimen, interfering with accurate results.
9. After the patient defecates, assist the patient out of the bathroom or off the commode, or remove the bedpan. Perform hand hygiene and put on disposable gloves.	Hand hygiene deters the spread of microorganisms. Gloves protect the nurse from microorganisms in feces.
If Using gFOBT:
10. Open the flap on the sample side of the card. With the wooden applicator, apply a small amount of stool from the center of the bowel movement onto one window of the testing card. With the opposite end of the wooden applicator, obtain another sample of stool from another area and apply a small amount of stool onto the second window of the testing card (Figure 1).	Two separate areas of the same stool sample are tested to ensure accuracy. By using opposite ends of the wooden applicator, cross-contamination is avoided.
11. Close the flap over the stool samples.	Closing the flap prevents contamination of the samples.
12. If sending the stool to the laboratory, label the specimen card per facility policy. Place it in a sealable plastic biohazard bag and send it to the laboratory immediately.	Facilities may allow point-of-service testing (at bedside or on unit), or the specimen may have to be sent to the laboratory for testing. Correct labeling is necessary to ensure accurate results. Packaging the specimen in a biohazard bag prevents the person transporting the container from coming in contact with the specimen.
13. If testing at the point of care, wait 3 to 5 minutes before developing. Open the flap on the opposite side of the card and place two drops of developer over each window and wait the time stated in the manufacturer's instructions (Figure 2).	If immediate testing is required, waiting 3 to 5 minutes before developing allows adequate time for the sample to penetrate the test paper and dry (Fischbach et al., 2022). The developer will react with any blood in the stool. Following the manufacturer's instructions promotes accuracy of results.
14. Observe the card for any blue areas (Figure 3).	Any blue coloring on the card indicates a positive test result for blood.
If Using FIT:
15. Open the flap on the sample side of the card. With the applicator, brush, or sampling probe, apply a small amount of stool from the center of the bowel movement onto the top half of the window of the testing card. With the opposite end of the device, obtain another sample of stool from another area and apply a small amount of stool onto the bottom half of the window of the testing card.	Two separate areas of the same stool sample are tested to ensure accuracy. By using opposite ends of the wooden applicator, cross-contamination is avoided.
16. Use the applicator to mix the samples and spread them over the entire window. Close the flap over the sample. Allow the card to dry.	Drying the samples stabilizes hemoglobin, if present.
17. If sending to the laboratory, label the specimen card per facility policy. Place it in a sealable plastic biohazard bag and send it to the laboratory immediately.	Facilities may allow point-of-service testing (at bedside or on unit), or the specimen may have to be sent to the laboratory for testing. Correct labeling is necessary to ensure accurate results. Packaging the specimen in a biohazard bag prevents the person transporting the container from coming in contact with the specimen.
18. If testing at the point of care, open the collection card according to the manufacturer's instructions. Add three drops of developer to the center of the sample on the sample pad. Developer should flow through the test (T) line and through the control (C) line. Snap the test device closed.	The developer will react with any blood in the stool. Following the manufacturer's instructions promotes accuracy of results.
19. Wait 5 minutes or the time specified by the manufacturer. Observe the card for a pink color on the test (T) line. The control (C) line must also turn pink within 5 minutes (Figure 4). If the control (C) line turns pink, read and communicate the result.	The developer will react with any blood in the stool. Following the manufacturer's instructions promotes accuracy of results. Any pink color on the test (T) line indicates a positive result.
20. After reading the results, discard the testing slide appropriately, according to facility policy. Remove your gloves and any other PPE, if used. Perform hand hygiene.	Proper removal of PPE reduces the risk for infection transmission and contamination of other items. Hand hygiene and proper disposal of equipment reduce the transmission of microorganisms.

Evaluation

The expected outcomes have been met when an uncontaminated stool sample has been obtained following collection guidelines and transported to the laboratory within the recommended time frame, and the patient has demonstrated accurate understanding of testing instructions and rationale for use.