ERCP test

ERCP stands for endoscopic retrograde cholangio pancreatography. It is a test to help diagnose conditions of the liver, bile ducts, pancreas or gallbladder.

What is an ERCP?

Your doctor uses a long flexible tube with a small camera and light at the end, called an endoscope. It's also sometimes called a duodenoscope. They pass this tube through your mouth, throat, stomach and into the first part of your small bowel (duodenum).

Your doctor can look down the endoscope or at pictures on a TV monitor. They also take x-rays of the pancreas, gallbladder and bile ducts.  

They can take samples (biopsies) of any abnormal looking areas.

The test takes between 15 minutes and 2 hours.

Diagram of an endoscopic retrograde cholangio pancreatography

Why you might have it

Having an ERCP helps your doctor find out what might be causing your symptoms. You might have this test:

  • if your blood tests show abnormal liver results
  • if you have severe inflammation of the pancreas (pancreatitis)
  • to help work out how big a tumour is (the stage)
  • if your doctor thinks there is a blockage in your bile ducts – this causes symptoms including yellowing of your skin and whites of your eyes, itchiness, tummy pain and dark coloured urine 

You might have an ERCP as part of your treatment. For example, if your bile or pancreatic ducts are blocked your doctor can use it to put a plastic or metal tube (stent) into the duct to relieve the blockage.

Preparing for an ERCP

Before the ERCP you usually have a blood test to check how well your blood clots.

Let the endoscopy department know if you're taking medicines to thin your blood such as warfarin. You might need to stop taking these medicines a number of days before the ERCP. Your doctor or nurse will tell you when you should stop.

You can't eat for 6 to 8 hours before the test. This is so that your stomach and duodenum are empty. You might be allowed to drink sips of water up to 2 hours before.

Because you have sedation for the test to make you drowsy, you will need someone with you to take you home and stay overnight. You shouldn’t drive, drink alcohol, operate heavy machinery or sign any legally binding documents for 24 hours.

It’s also a good idea to bring an overnight bag just in case you need to stay in hospital overnight.

How you have an ERCP

Just before the test

Your appointment letter tells you where to go. You usually go to the endoscopy department to have this test but you might have it in the x-ray department.

Before the procedure you see the doctor. They explain the procedure to you and ask you to sign a consent form. This is a good time to ask any questions you may have. 

You usually change into a hospital gown and remove any jewellery or metal objects on your body. As this will interfere with the x-ray pictures they take.  

You lie on the bed or x-ray couch. The nurse puts a small plastic tube (cannula) into the back of one of your hands. You may have antibiotics to prevent infection and fluids through a drip.

Your nurse gives you a plastic mouth guard to wear. This is to protect your teeth and gums during the test. They also give you oxygen through a tube that fits into your nose (nasal cannula).

During the test

You usually have an injection of sedation first to make you very drowsy. Your doctor might spray the back of your throat with a local anaesthetic to make it easier to swallow the endoscopy tube.

Once the sedative has worked, your doctor passes the endoscope tube through your mouth, down your throat into your stomach. They'll ask you to swallow as the tube goes down. You will be able to breathe normally, but you may gag slightly.

Once in the stomach, it then goes into your duodenum. This is where the pancreatic and bile ducts join. They might put a small amount of air into your stomach to help them see more clearly. This can make some people feel uncomfortable and like you want to burp.

They pass a thinner tube down through the endoscope which can fit into your bile duct. They then inject dye (contrast medium) through the tubes into the channels (ducts) of the biliary tree and pancreas so they can see them on x-ray pictures.

Your doctor can take samples of cells from the bile ducts using a brush (brush cytology). And they may also take pieces of tissue (biopsies). They send these samples to the laboratory for examination under a microscope. They may also take some photographs.

Your nurse checks your heart rate, breathing rate and oxygen levels throughout the test.

Detailed diagram of an endoscopic retrograde cholangic pancreatography (ERCP)

After the test

Your doctor removes the tube. You then need to rest for a while. You might need to stay in the department for a few hours.

You might not remember much (if anything) about the test when you wake up from the sedation.

After the test you might:

  • have a sore throat for a few days
  • have bloating and discomfort in your tummy (abdomen) for a short time
  • feel sick or be sick after the sedation

Your nurse removes the cannula from your hand before you leave. You should be able to go home the same day. You won't be able to drive for the rest of the day and should have someone to go home with you and stay overnight.

Possible risks

ERCP is generally a safe procedure but as with any medical procedure, there are possible risks. Your doctor makes sure the benefits of the test outweigh these risks.

Inflammation of the pancreas (pancreatitis)

You may have pain in your tummy (abdomen) after this test. Your doctor can give you painkillers to help control this. It's important to tell your nurse or doctor if you get pain in your abdomen. 


There's a risk of infection with this test. If you get a temperature or generally feel unwell contact your doctor.  


There may be some bleeding from having an ERCP which usually stops on its own. In some cases this can be severe and you will need medicine to stop it and maybe a blood transfusion. 

Allergic reaction

There is a risk of having an allergic reaction to the sedation or dye. This can cause problems with your breathing, heart rate and blood pressure. If this happens, the staff will give you medicines to control the reaction. 

Tear in your bowel

Very rarely there is a small tear (perforation) in the first part of your small bowel. If this happens it’s likely you would need surgery to repair the tear.

Exposure to radiation

The amount of radiation you receive from the x-rays during the test is small and doesn't make you feel unwell. Exposure to radiation during an x-ray can slightly increase your risk of developing cancer in the future. Talk to your doctor if this worries you.

When to contact a doctor

Contact the hospital where you had the ERCP or go the accident and emergency department (A&E) if you have:

  • ongoing or severe pain in your abdomen
  • a high temperature
  • yellowing of the skin (jaundice), if you didn't have it before
  • black poo (this can be a sign of blood in your poo)
  • being sick and are unable to stop

Getting your results

You should get your results within 1 or 2 weeks at a follow up appointment. 

Waiting for test results can be a very worrying time. You might have contact details for a specialist nurse who you can contact for information if you need to. It can help to talk to a close friend or relative about how you feel.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040 for information and support. The lines are open from 9am to 5pm, Monday to Friday.

Contact the doctor who arranged the test if you haven’t heard anything after a couple of weeks.

More information

We have more information on tests, treatment and support if you have been diagnosed with cancer.

Last reviewed: 
15 Mar 2019
  • Endoscopic retrograde cholangiopancreatography: Indications, patient preparation, and complications
    Up To Date, Accessed July 2018

  • ERCP: The Fundamentals (2nd Edition)
    P B Cotton and J Leung
    Wiley Blackwell, 2015

  • ERCP (2nd Edition)
    T H Baron and others
    Elsevier Saunders, 2013

  • Urgent endoscopic retrograde cholangiopancreatography is not superior to early ERCP in acute biliary pancreatitis with biliary obstruction without cholangitis
    H S Lee and others
    PLoS, 2018. Volume 13, Issue 2

  • Qualification for endoscopic retrograde cholangiopancreatography in the diagnosis and treatment of extrahepatic cholestasis caused by choledocholithiasis
    K Kujawski and others
    Archives of Medical Science, 2015. Volume 11, Issue 6, Pages 1213 - 1216

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.