SeHCAT – bile acid function test

What is the SeHCAT test?

The SeHCAT test is used to determine whether your body is absorbing bile acids properly.
If they are not absorbed well, they can enter the large intestine and cause recurrent watery diarrhoea, abdominal pain, bloating or nausea.

SeHCAT is a simple, painless and safe test that is performed at a nuclear medicine facility.

When is the test performed?

Your doctor will recommend the test if you have:

• long-term diarrhoea of unknown cause,
• problems after gallbladder removal,
• small intestine disease (e.g. Crohn's disease),
• after surgery or inflammation of the small intestine,
• suspected bile acid malabsorption.

The examination often helps to distinguish between irritable bowel syndrome (IBS-D) and bile malabsorption.

How is the test performed?

Day 1 – capsule administration and first measurement

• At the clinic, you will receive a small capsule containing a minimal amount of the radioactive substance SeHCAT.
   It does not cause allergies, diarrhoea or pain.
• Swallow the capsule with water.
• After about 3 hours, we will perform the first short measurement using a gamma camera (3–5 minutes).

Day 7 – second measurement

• You will return to the clinic in a week.
• A second measurement will be taken, again within a few minutes.
• No injection or additional capsules are required.

Evaluation

The doctor will compare both measurements and determine how much bile acid your body has "retained" after a week.

How to prepare for the examination?

• You do not need to fast.
• You can take your usual medication, except for bile acid sequestrants (e.g. cholestyramine) – these must be discontinued at least 7 days before the test, in consultation with your doctor.
• No special dietary measures are necessary.
• The examination is painless, does not burden you and takes only a few minutes on both the first and seventh days.

Is the examination safe?

• Yes. The radioactive substance used has a very low radiation dose, significantly lower than a standard CT scan.
• The substance does not participate in metabolism, does not cause allergies and does not cause digestive problems.
• Pregnant women cannot undergo the examination.
• Breastfeeding women are advised to stop breastfeeding for 24 hours.

What do the results mean?

• Normal function: the body retains the substance – usually more than 15%.
• Reduced absorption: the body does not retain bile acids → probable malabsorption of bile acids.
• Very low retention: severe disorder, often after surgery or in cases of small intestine inflammation.

Based on the result, your doctor may recommend treatment, which usually involves bile acid-binding medication and often leads to a significant improvement or complete disappearance of diarrhoea.

Advantages of the test for you

• Non-invasive, painless and simple.
• High accuracy.
• Helps determine the cause of long-term digestive problems.
• Enables targeted treatment, which often helps very quickly.

Summary

The SeHCAT test will help you determine whether your problems are related to bile acid malabsorption. It is a quick, safe and highly accurate test that allows your doctor to prescribe the right treatment and improve your quality of life.