Stool Test - A Review

Introduction

Stool testing is a basic test involving examining feces in the laboratory to diagnose various gastrointestinal infections and conditions. It is non-invasive and relatively simple but offers critical information regarding gut health. This article aims to explain stool testing, giving information on its uses, procedure of testing, and results interpretation.

What Is Stool Testing?

Stool testing refers to the diagnostic procedures involved in assessing and analyzing the fecal sample with the intent to look into gut health. The test is important in diagnosing most infections, inflammatory conditions, and disorders and screening colon cancer. The presence of inflammatory markers, fat, blood, pathogens, and parasites can all be analyzed using these tests. It helps give an insight into gastrointestinal health from a laboratory view. Macroscopic analysis is also conducted in infants and newborn babies to assess their health.

What Are the Uses of Stool Testing?

Physicians have utilized stool tests for years to recognize various infections and conditions related to the gut system. It is very important to perform stool tests at the proper timing, as it enables clinicians to better diagnose and manage gastrointestinal health. Routine testing facilitates a proactive approach to guarding gut health. This helps in personalized medicine and optimized patient care.

Some of the important uses of testing stool specimens are

1. To Detect Infections of the Gut: Numerous infections, such as Salmonella (causing Salmonellosis), Campylobacter (causing bacterial gastroenteritis), Shigella ( Shigellosis), Escherichia coli (food outbreaks, hemorrhagic colitis, hemolytic uremia syndrome), Giardia (Giardiasis), and Cryptosporidium (Cryptosporidiosis), can be detected in stools. Some infections have serious complications, and early diagnosis can greatly help.

2. To Diagnose Disorders of Digestion: Testing the stool specimens allows clinicians to detect any underlying gastrointestinal disorders, such as inflammatory bowel disease, Crohn’s disease, and Celiac disease. The stool is assessed for blood, mucus, fat, or inflammatory markers. The presence of these in the stool indicates disease and needs immediate action.

3. Routine Testing: Routine stool testing is essential to monitor gastrointestinal health regularly. In individuals with certain diseases, stool testing helps monitor disease progress and measure treatment effectiveness.

4. Cancer Screening: Tests such as fecal occult blood tests and fecal immunochemical tests are stool tests utilized in screening for colon cancer. The tests catch any hidden blood in stool that may indicate cancerous polyps and lesions.

What Are the Types of Stool Tests Done?

Various stool tests are performed to assess the different pathogens and disorders related to the gastrointestinal system.

1. Culture and Sensitivity Tests: This test lets the clinician look for pathogens causing gastrointestinal infections. It helps identify the strains and guides in choosing appropriate antibiotic treatment.

2. Parasite Examination: Ova and parasite tests detect parasites such as Giardia lamblia and Entamoeba histolytica and worms like hookworms. The eggs and larvae can also be identified and diagnosed using microscopy.

3. Fecal Occult Blood: A blood screening test detects blood in the stool. It is useful in detecting cancers and polyps.

4. Stool pH Measurement: It provides information on the acidity and alkalinity of stool, which gastrointestinal disorders can significantly alter.

5. Macroscopic Tests: Stool samples are assessed for color, quantity, form, odor, and consistency. Black-colored stools indicate iron or bismuth treatment and red-colored stools are common with lower gastrointestinal bleeding. The Modified Bristol visual stool scale may be used in newborns to compare stool consistency and diagnose normality.

What Are the Indications of Stool Testing?

Stool testing is indicated for numerous reasons to evaluate gastrointestinal health. Some indications include:

1. Symptoms such as:

• Diarrhea.

• Constipation.

• Pain.

• Cramps.

• Nausea.

• Vomiting.

• Flatulence.

• Acute gastroenteritis (diarrhea with fever).

• Food outbreaks.

• Suspected parasite.

In individuals with chronic gastrointestinal issues, monitor the progress.

1. For screening of cancers.

2. To evaluate pancreatic disorders like chronic pancreatitis.

3. To evaluate unexplained symptoms related to the gut.

4. To evaluate suspected gastrointestinal bleeding, which can be visible blood or occult (hidden) blood.

How Is It Performed?

The steps involved in stool testing include:

1. Collecting Sample: Patients are asked to collect stool samples in a clean, sterile, dry container. Generally, a small quantity is sufficient. The healthcare provider will explain the collection method, transportation, and storage-related information. It is very important to adhere to the instructions provided to avoid contamination.

2. Transportation: It is essential to transport the collected sample to the laboratory as soon as possible to avoid contamination. Sometimes, the sample might need refrigeration or preservation with certain solutions. The instructions must be followed.

3. Processing: The technician then processes the sample using techniques such as homogenization and dilution. Based on the test ordered, culture, microscopy, antigen detection, molecular techniques like polymerase chain reaction, or biochemical assays might be done to analyze the sample.

4. Analysis: The sample is analyzed for abnormalities or the presence of microorganisms, blood, or fat. The results are then formulated and made into a report.

How Are the Test Results Interpreted?

1. When a pathogenic microorganism is positive, the type and quantity are noted. This helps guide treatment strategies, such as antibiotics and antiparasitics.

2. In cases where the inflammatory marker levels are increased in stool, consideration must be given to inflammatory conditions such as inflammatory bowel disease flare-ups. The markers checked are usually fecal calprotectin, lactoferrin, etc.

3. The presence of blood in the stool is indicative of some bleeding in the gastrointestinal tract. This could be a result of polyps, hemorrhoids, cancer, etc. When blood is positive in stool, further tests like colonoscopy are indicated to confirm the cause and start early intervention.

4. The presence of fat in stool is referred to as steatorrhea and is indicative of malabsorption diseases like bile acid malabsorption, celiac disease, etc.

Conclusion

Testing stool samples is a valuable tool in evaluating the gastrointestinal system's health. Understanding these tests' uses, indications, and interpretation helps healthcare providers better care for patients. When stool test results are taken along with clinical symptoms and examination, it helps in effective diagnosis and best interventional management of cases. Regular screening and monitoring using stool tests are important in maintaining gastrointestinal health and preventing all sorts of complications associated with gastrointestinal disorders.