Foul-Smelling Stools: Which Blood Tests to Run and Why

Foul-smelling stools can be unsettling and might signal an underlying health issue. While dietary changes can sometimes cause this symptom, persistent or severe cases may require further investigation. Blood tests can help identify potential causes by assessing various aspects of your health.

What are foul-smelling stools?

Foul-smelling stools are bowel movements that have an unusually strong, unpleasant odor. This can result from various conditions, including digestive disorders, infections, or dietary factors. While occasional changes in stool odor are common, persistent foul-smelling stools warrant further attention.

Why do foul-smelling stools matter?

The odor of your stool can provide clues about your digestive health. Foul-smelling stools can indicate malabsorption, where your body is not effectively absorbing nutrients from food. They can also suggest infections, such as those caused by bacteria or parasites, or indicate chronic conditions like celiac disease or inflammatory bowel disease (IBD).

Blood tests to consider

Several blood tests can help determine the cause of foul-smelling stools:

• Complete Blood Count (CBC): This test measures different components of your blood, including red and white blood cells and platelets. It can help identify infections or inflammation, which might contribute to digestive issues.

• C-reactive protein (CRP): CRP is a marker of inflammation in the body. Elevated levels can suggest an inflammatory condition, such as IBD, which might be responsible for foul-smelling stools.

• Liver function tests (LFTs): These tests assess how well your liver is working. Liver issues can affect digestion and lead to changes in stool odor.

• Celiac disease panel: This series of blood tests can detect antibodies associated with celiac disease, a condition where gluten ingestion leads to intestinal damage and malabsorption.

• Thyroid function tests: The thyroid gland regulates metabolism, and dysfunction can impact digestion. Testing thyroid hormone levels can reveal if an imbalance is contributing to your symptoms.

How to interpret blood test results

Blood test results should be interpreted in the context of your overall health and symptoms. Normal ranges for test results can vary slightly depending on the laboratory and individual factors like age and gender. It's important to discuss your results with a healthcare provider to understand their significance and determine any necessary next steps.

Frequently asked questions

Can diet alone cause foul-smelling stools? Yes, certain foods, such as those high in sulfur (e.g., eggs, meat), can cause foul-smelling stools. However, if the odor persists, it may indicate a more serious issue.

Are foul-smelling stools always a sign of illness? Not always. Occasional changes in stool odor can be normal, especially after dietary changes. Persistent or severe symptoms, however, should be evaluated by a healthcare provider.

Do I need to fast before these blood tests? Some blood tests do require fasting, such as certain liver function tests. Your healthcare provider will inform you if fasting is necessary for your specific tests.

When to see a doctor

If you experience persistent foul-smelling stools, especially along with other symptoms like abdominal pain, weight loss, or diarrhea, it's important to consult a healthcare provider. They can help determine the underlying cause and recommend appropriate tests or treatments.

Remember, this information is for educational purposes only. Always discuss your health concerns and test results with a healthcare provider.