Fecal Analysis

Fecal Analysis

Common use

Specimen

Normal findings

Description

This procedure is contraindicated for

N/A

Indications

• Assist in diagnosing disorders associated with GI bleeding or drug therapy that leads to bleeding
• Assist in the diagnosis of pseudomembranous enterocolitis after use of broad-spectrum antibiotic therapy
• Assist in the diagnosis of suspected inflammatory bowel disorder
• Detect altered protein digestion
• Detect intestinal parasitic infestation, as indicated by diarrhea of unknown cause
• Investigate diarrhea of unknown cause
• Monitor effectiveness of therapy for intestinal malabsorption or pancreatic insufficiency
• Screen for cystic fibrosis

Potential diagnosis

Critical findings

N/A

Interfering factors

• Drugs that can cause positive results for occult blood include acetylsalicylic acid, anticoagulants, colchicine, corticosteroids, iron preparations, and phenylbutazone.
• Ingestion of a diet high in red meat, certain vegetables, and bananas can cause false-positive results for occult blood.
• Large doses of vitamin C can cause false-negative occult blood.
• Constipated stools may not indicate any trypsin activity owing to extended exposure to intestinal bacteria.

Nursing Implications and Procedure

Potential nursing problems

Pretest

• Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
• Patient Teaching: Inform the patient this test can assist in the diagnosis of intestinal disorders.
• Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
• Obtain a history of the patient’s gastrointestinal system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
• Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
• Review the procedure with the patient. Inform the patient of the procedure for collecting a stool sample, including the importance of good hand-washing techniques. The patient should place the sample in a tightly covered container. Instruct the patient not to contaminate the specimen with urine, water, or toilet tissue. Address concerns about pain and explain that there should be no discomfort during the procedure.
• Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
• Instruct the patient not to use laxatives, enemas, or suppositories for 3 days before the test.
• Instruct the patient to follow a normal diet. If the test is being performed to identify blood, instruct the patient to follow a special diet that includes small amounts of chicken, turkey, and tuna (no red meats), raw and cooked vegetables and fruits, and bran cereal for several days before the test. Foods to avoid with the special diet include beets, turnips, cauliflower, broccoli, bananas, parsnips, and cantaloupe, because these foods can interfere with the occult blood test.

Intratest

• Potential complications: N/A
• Ensure that the patient has complied with medication restrictions; assure laxatives, enemas, or suppositories have been restricted for at least 3 days prior to the procedure.
• Instruct the patient to cooperate fully and to follow directions.
• Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date and time of collection, and suspected cause of enteritis; note any current or recent antibiotic therapy.
• Collect a stool specimen in a half-pint waterproof container with a tight-fitting lid; if the patient is not ambulatory, collect it in a clean, dry bedpan. Use a tongue blade to transfer the specimen to the container, and include any mucoid and bloody portions. Collect specimen from the first, middle, and last portion of the stool. The specimen should be refrigerated if it will not be transported to the laboratory within 4 hr after collection.
• To collect specimen by rectal swab, insert the swab past the anal sphincter, rotate gently, and withdraw. Place the swab in the appropriate container.
• Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

• Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
• The American Cancer Society recommends regular screening for colon cancer, beginning at age 50 yr for individuals without identified risk factors. Their recommendations for frequency of screening: annual for occult blood testing (fecal occult blood testing [FOBT] and fecal immunochemical testing [FIT]); every 5 yr for flexible sigmoidoscopy, double contrast barium enema, and CT colonography; and every 10 yr for colonoscopy. There are both advantages and disadvantages to the screening tests that are available today. Methods to use DNA testing of stool are being investigated and await FDA approval. The DNA test is designed to identify abnormal changes in DNA from the cells in the lining of the colon that are normally shed and excreted in stool. The DNA tests under development use multiple markers to identify colon cancers that demonstrate different, abnormal DNA changes. Unlike some of the current screening methods, the DNA tests would be able to detect precancerous polyps. The most current guidelines for colon cancer screening of the general population as well as of individuals with increased risk are available from the American Cancer Society (www.cancer.org), U.S. Preventive Services Task Force (www.uspreventiveservicestaskforce.org), and the American College of Gastroenterology (www.gi.org). Answer any questions or address any concerns voiced by the patient or family.
• Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

• Patient Education

  • Recognize anxiety related to test results.
  • Discuss the implications of abnormal test results on the patient’s lifestyle.
  • Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
  • Note that decisions regarding the need for and frequency of occult blood testing, colonoscopy, or other cancer screening procedures should be made after consultation

• Expected Patient Outcomes

  • Knowledge
  • States the importance of notifying the HCP of black or tarry stools
  • States understanding that untreated disease could result in colon cancer
  • Skills
  • Demonstrates proficiency in the self-administration of ordered vitamin supplements
  • Demonstrates the ability to select a diet that will support bowel health and decrease gastric irritation
  • Attitude
  • Complies with the request to adjust diet to decrease abdominal pain and improve caloric intake
  • Complies with the request to provide a stool specimen for analysis in a timely manner

Related Monographs

• Related tests include α₁-antitrypsin/phenotyping, barium enema, biopsy intestine, capsule endoscopy, CEA and cancer antigens, chloride sweat, colonoscopy, CT colonoscopy, culture stool, d-xylose tolerance, fecal fat, gliadin antibody, lactose tolerance test, ova and parasites, and proctosigmoidoscopy.
• Refer to the Gastrointestinal System table at the end of the book for related tests by body system.