Blood tests
Blood tests can assist us in diagnosing diseases of the gastrointestinal (GI) tract. At Digestive Health UK, we offer private blood tests to ease your concerns, assess your general health, and help us identify the cause of your symptoms. Book a consultation at either of our London clinics to see if you need a blood test.
Preparing for a blood test
Unless our specialist provides specific instructions, you should be able to eat and drink as normal before a blood test. Changing your diet, for example, avoiding gluten beforehand, could alter your test results and prevent us from finding the cause of your problems.
You may need to fast (stop eating and drinking) for 8 to 12 hours before your test. Common tests that often require fasting include those checking your cholesterol, such as HDL and LDL, and blood sugar.
We recommend you do not drink alcohol for at least 24 hours prior. You should still drink water to stay hydrated, which will help us find a vein. You might also need to avoid smoking a few hours before or stop taking certain medications. We will let you know if you should change your medication and for how long before the test.
We may need to order another blood test if you accidentally eat or take medication before your test, so make sure you follow the directions provided by our specialist.
Do you dislike or fear needles?
Although blood tests are quite straightforward, some people dislike or fear needles, which can make the test more daunting. This is a common fear, and there is nothing to be ashamed of. Let us know beforehand if you usually feel uncomfortable or nervous. We can take steps to increase your comfort and make the process less stressful for you.
What happens during a blood test?
Before your blood test, we might wrap a tourniquet (a tight rubber band) around your arm, which makes it easier to find a good vein. We usually take blood from your inner elbow or wrist, depending on where the best vein is.
We will sterilise your skin and use a small needle to collect your blood sample. As we insert the needle, you might experience a slight sting or pricking sensation, but you should not feel pain. If it’s hard to find a vein, you may need a different type of needle in the back of your hand called a butterfly needle.
After we have taken the sample, we’ll remove the tourniquet and apply pressure with a piece of gauze for a few minutes. Pressing on the insertion site with gauze helps the blood clot, allowing the area to heal quicker. We may then put a small plaster over it.
Aftercare
After a blood test, you may have a minor bruise, but many people experience no side effects and do not require further aftercare. Some people feel a bit dizzy or sick after, and it can help to have something to eat, such as a banana or biscuit, to increase your blood sugar.
In 2.5% of cases, people faint during or straight after the test. We call this a vasovagal response, which means your blood pressure has dropped suddenly. If you do faint, you might have pale skin, a cold sweat, or feel ill. While it can be scary, it’s usually nothing to worry about.
Types
There are many acronyms associated with blood tests, which can be confusing, and it can be hard to understand why you are having one. Below we list some of the different types, their common acronyms, and their purpose.
Mean corpuscular haemoglobin (MCH): Measures the average amount of haemoglobin in your red blood cells and can diagnose different types of anaemia.
Full blood count (FBC, CBC): Identifies how many white blood cells, red blood cells and platelets you have and gives further information on them.
Ferritin blood test: Measures how much ferritin, a protein that stores iron, is in your blood.
Helicobacter pylori (H. pylori) test: Looks for H. pylori antibodies, though we more commonly use a stool test.
C reactive protein (CRP): Indicates whether you have inflammation.
If you don’t understand why you are having a blood test or what it can tell us, please ask our specialist to explain it to you. Depending on your symptoms, we may recommend other tests, such as a stool test, alongside a blood test to aid our diagnosis.
What can a blood test tell us?
We often use this test to investigate suspected bacterial or parasitic infections or certain conditions, such as coeliac disease, inflammatory bowel disease (IBD), and liver problems. You may need a full blood count, which is a routine test that can indicate signs of anaemia, blood-clotting issues, some cancers, such as stomach cancer or bowel cancer (can cause anaemia), immune system disorders, and infections.
We can also use blood tests to assess how well your liver, kidney, and thyroid function; evaluate your vitamin and hormone levels; and perform a pancreatic enzyme test to check if everything works efficiently. We may also take blood tests to rule out other diseases and help pinpoint the exact cause of your illness.
Blood test results
Your results may take between 3 and 10 days to receive, depending on the type of blood tests needed and medical urgency, but it is usually only a few days. We will discuss your results and plan our next steps in a follow-up consultation. We can also email your results before the appointment if you’d like to look before you visit our clinic. If you would prefer a virtual follow-up or phone call, we can also accommodate this.
Our specialist will let you know if you do not need a follow-up appointment and can send a letter summarising your results. We may recommend this if you are having a general health check and we have no concerns or unusual findings.
FAQs
Book a private blood test
Blood tests are one of many tests that can allow us to assess your general and gastrointestinal health. Our specialist may recommend one if you are experiencing symptoms of a gastrointestinal condition, such as coeliac disease or IBD.
Contact our clinic if you are experiencing gastrointestinal issues. You will have a thorough consultation with one of our specialists to discuss your symptoms and medical history to determine the possible cause.