Getting diagnosed

Most people start by seeing their GP. They may arrange for you to have tests such as an endoscopy, scans and blood tests. Many people are diagnosed with a small bowel NET when they have tests for something else.

Seeing your GP

You usually start by seeing your GP. They will ask you about your general health, symptoms and might also examine you.

Your GP might check your blood pressure, heart rate and temperature. They might arrange for you to have blood tests or an x-ray. Your doctor will then decide if you need to see a specialist.

Seeing a specialist

Your GP looks at your symptoms and decides which specialist to refer you to. For example, they might refer you to a gastroenterology specialist if you are having symptoms such as tummy (abdominal) pain.  

Many people with a small bowel NET do not have any symptoms. So, you might be diagnosed with a NET during tests for another condition. If tests show that you have a small bowel NET, your specialist will refer you to a team of doctors and nurses who have expertise in treating NETs. 


You have tests to check the type of NET you have, the size of the tumour and whether it has spread. This helps your team plan your treatment.

Tests you might have include:

Blood tests

Blood tests can check your general health. They can also check the levels of certain substances in the blood which are sometimes raised with NETs.

Urine tests

Rarely, certain stomach NETs release high amounts of serotonin. This breaks down into a substance called 5-HIAA. Your doctor can test for this in your wee (urine).

CT scan

This scan can show up a NET and see whether it has spread anywhere else in your body.

MRI scan

An MRI scan can show up a NET and see whether it has spread.

PET scan

A PET scan can show the size of a small bowel NET and whether it has spread. There are several different types of PET scans. Your team can explain which scan you are having and why.

Ultrasound scan of the tummy area (abdomen)

Ultrasound scans use high frequency sound waves to build up a picture of the inside of the body.

The sound waves bounce off the organs inside your body, and the microphone picks them up. The microphone links to a computer that turns the sound waves into a picture on the screen.

Radioactive scans

These are octreotide scans (or octreoscans) and MIBG scans. You have an injection of a low dose radioactive substance, which is taken up by some NET cells. The cells then show up on the scan.


A colonoscopy looks at the whole of the inside of the large bowel. A doctor or nurse (colonoscopist) uses a flexible tube called a colonoscope. The tube has a small light and camera at one end. The colonoscopist puts the tube into your back passage and passes it along the bowel. They can see pictures of the inside of your bowel on a TV monitor.

Endoscopy (gastroscopy)

An endoscopy is a test that looks inside the body. The endoscope is a long flexible tube which has a tiny camera and light on the end of it.  A doctor or specialist nurse looks down the endoscope to see if there are any growths or other abnormal looking areas. 

The doctor or nurse can also take samples of any abnormal looking tissue through the endoscope.

You might also have a test called a capsule endoscopy. You swallow a small disposable camera which is inside a capsule. The capsule is the size of a large pill. The camera takes thousands of pictures as it travels along your gut. The pictures are transmitted wirelessly to a data recorder that you wear on a belt around your waist.


A biopsy means taking a sample of cells from your small bowel to look at under a microscope. You might have a sample taken during surgery or an endoscopy. 

Your doctor might also take a sample of cells from your liver to see if NET cells have spread there. They use an ultrasound scan to make sure they take a sample from the right place.

A test to check your heart (echocardiogram)

This is an ultrasound scan of the heart. It uses sound waves to form a picture. Doctors can look at the structure of your heart and how well it is pumping.

You might have other tests, depending on your symptoms. Your doctor can tell you which tests you need.
Last reviewed: 
09 Jun 2021
Next review due: 
09 Jun 2024
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  • ENETS consensus guidelines update for neuroendocrine neoplasms of the jejunum and ileum
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