FIT or Calprotectin: What the Stool Tests Measure

When a clinic asks for a stool sample, write the test name beside the collection instructions. A pot or tube alone does not explain what the laboratory is checking. Knowing the name helps you ask about the reason for testing and the follow-up.

FIT: checking for blood

Cancer Matters Wessex¹ describes FIT as part of investigating symptoms that could be caused by bowel cancer. Its result helps the doctor decide whether further tests are needed. Blood can have other causes; finding it does not, by itself, establish cancer.¹

Ask whether your test is part of symptom assessment or routine screening. The Wessex guidance distinguishes those uses. Tell the ordering team about your current symptoms, even if you have recently completed a screening test.¹

Before collecting, confirm where to return the kit and how you will receive the result. Put the clinic’s contact details with the instructions.

Calprotectin: checking for intestinal inflammation

UCLH explains that calprotectin in stool is a useful marker for inflammatory bowel disease, including Crohn’s disease and ulcerative colitis. Testing can help assess active inflammation, with further investigations used to understand its source.²

A raised result can sometimes be false, and the team may arrange a repeat sample or further investigation. Ask how the finding fits your symptoms and what step is planned next. Avoid applying another laboratory’s numbers to your own report.²

For collection, follow the directions supplied by your service. UCLH emphasizes keeping the sample out of toilet water because contamination can affect the result. Confirm the container, labeling and return requirements for your own kit rather than copying another hospital’s process.²

Keep a plan for symptoms that continue

A normal FIT does not completely rule out cancer. Wessex advises returning to the doctor if symptoms continue, change or worsen, even after normal results. Further tests may still be appropriate. Agree on how to report those changes and who will review them.¹

Keep the test name, collection date, result and planned next step together. If more than one stool test was ordered, ask the team to explain each result separately and how the findings fit the overall assessment.

Bloated by Dinner includes a Belly Clock log and Test It list with a visit script. Use them to organize symptom timing and testing questions alongside your clinical records. See the book.