ERCP test

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

What is an ERCP?

Your doctor puts a tube called an endoscope down your throat to take x-rays of the pancreas, gallbladder and bile ducts. The endoscope is a long flexible tube with a small camera and light at the end.

The doctor can look down the endoscope or at pictures on a TV monitor. The test takes between 30 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.


In some hospitals during an ERCP, your doctor puts a smaller tube down a channel in the endoscope. This smaller tube has a probe and camera attached (cholangioscope). It can go directly into the bile ducts so the doctor can see if there are any abnormal areas and take biopsies. 

Cholangioscopy may be better than ERCP alone in helping pick up abnormal areas that might be due to cancer, and helps your doctor in targeting where to take biopsies from.

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 the results within 1 or 2 weeks.

Usually the doctor who does the ERCP writes a report straight way. They send the report to your specialist, who gives the results to you. If your GP has sent you for the test, the results are sent directly to the GP surgery.

Waiting for results can be an anxious time. It might be helpful to talk to someone close to you. 

If it isn't an emergency and you haven't had your results a few weeks after your test, contact your doctor to chase your results for you.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9 to 5, from Monday to Friday.
Last reviewed: 
30 Nov 2020
Next review due: 
30 Nov 2023
  • ERCP Endoscopic Retrograde Cholangiopancreatography
    UpToDate, Accessed January 2021

  • Biliary cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow up
    JW Valle and others
    Annals of Oncology, 2016. Volume 27, Pages 28-37

  • Guidelines for the diagnosis and treatment of cholangiocarcinoma: an update
    SA Khan and others 
    Gut, 2012. Volume 61, Pages 1657-1669