Having an ERCP

ERCP (endoscopic retrograde cholangio pancreatography)

During an ERCP, we put a flexible tube called an endoscope with a camera on the end into your mouth. We then pass this tube down your food pipe (oesophagus). The tube goes into your stomach and the first part of your small intestine (duodenum).

The procedure lasts between 15 minutes and 1 hour 30 minutes. The average time is 30 minutes.

An ERCP can be used to:

  • take samples of your cells with a small brush or by removing pieces of tissue (a biopsy). A laboratory then examines these cells to diagnose any problems
  • put small plastic or metal tubes (stents) into your bile ducts or small intestine. This helps to drain bile (a fluid used to digest fat) or treat a blockage affecting the flow of food out of the stomach
  • remove pancreatic stones or put a stent into a narrowed pancreatic duct, which can help with pain

Read more about how we use an ERCP to diagnose and treat conditions

Preparing for an ERCP

It is best to wear loose-fitting clothes on the day of your ERCP.

Before you have the ERCP, you need a blood test. This is to check:

  • how well your blood clots
  • your blood count (the types and numbers of cells in your blood)

Instructions for sedation and general anaesthetic

You usually have sedation or a general anaesthetic for an ERCP.

Sedation is a medicine to make you relaxed during the procedure. It might make you sleepy (drowsy), but you will not be asleep. You can hear what we say to you and respond to any instructions.

A general anaesthetic is a medicine that gives a state of controlled unconsciousness. This is like being asleep and you do not feel pain.

If you leave hospital within 24 hours after the ERCP, you must have someone to take you home and stay with you overnight.

The person who takes you home after the procedure must be at least 18 years old. They should come with you for the appointment. Otherwise, we need to be able to contact them by phone when you are ready to leave hospital.

If you do not have someone to take you home and stay with you overnight, your procedure might be cancelled.

If you cannot arrange for someone to collect you, please contact us to talk about other possible arrangements.

Eating and drinking

  • Do not eat anything for 6 hours before the ERCP. Your stomach and small intestine must be empty for the doctor to have a clear view with the camera.
  • Do not drink anything for 4 hours before your appointment. However, you can have small sips of water for up to 2 hours before the appointment.

Usual medicines

You talk to your doctor or nurse about any medicines that you take before the procedure. Tell your doctor or nurse if:

  • you take any regular medicines, including medicines that you buy at a pharmacy or shop and any herbal or homeopathic medicines
  • you have allergies to any medicines
  • you take antiplatelet or anticoagulant medicine that thins your blood, such as aspirin, clopidogrel, warfarin or rivaroxaban. You might need to stop taking this medicine for a short time before your procedure
  • you take sedatives, chronic pain medicine or medicines for diabetes. You might need to change the amount (dose) of your medicine for a short time before the procedure

Keep taking all of your medicines as usual, unless the doctor or nurse tells you otherwise.

We give you more information about stopping any medicines at your pre-assessment appointment. This is an appointment to check your general health and fitness before you can have the procedure.

If you have any questions about your medicines, please speak to your doctor or nurse.

Arriving at the endoscopy unit

When you arrive at the endoscopy unit, please give your name to the receptionist. They ask you to sit in the waiting area until an endoscopy nurse is ready to see you.

The nurse asks you about your medical history (your present and past conditions and treatments). Please tell them if other procedures in the past caused any reactions or allergies.

We ask you to take off all your jewellery. This is because you should not wear any metal during the procedure. You might want to leave any valuable jewellery at home. We cannot be responsible for any valuable items lost while in the unit. 

We ask you to remove all of your clothes and change into a gown and some dignity disposable underwear. You might want to bring your dressing gown and slippers with you. We give you non-slip socks.

When you are ready, we take you to the second waiting area. This is signposted as the ‘sub wait area’.

Your doctor explains more about the procedure and answers any questions that you have.

Waiting times

Our endoscopy teams run up to 5 procedure rooms at the same time. Sometimes, a person who arrived after you might be called in before you. This does not mean that we have forgotten you. It means that the other person is on a different list to you.

We do everything that we can to avoid keeping you waiting any longer than necessary. However, as every procedure takes a different length of time, it is sometimes hard to give exact timings.

We also deal with emergencies. These can take priority over your appointment and we might have to ask you to wait.

We update you regularly on the likely waiting time. Please be prepared to be with us for the whole morning or whole afternoon, depending on the time of your appointment.

Please be patient with us and check at the reception desk if you are concerned.

During an ERCP

The procedure lasts between 15 minutes and 1 hour 30 minutes. The average time is 30 minutes.

We usually give you an antibiotic to take 1 hour before the ERCP. You can swallow this with a small amount of water.

  1. A nurse attaches monitors to one of your fingers. These record your pulse, oxygen level, blood pressure and heart rhythm. 
  2. We might give you a local anaesthetic throat spray to make your throat numb.
  3. You need to lie on your left side.
  4. We put a plastic mouthguard in your mouth. This allows us to pass a tube through your mouth and give you oxygen during the procedure.
  5. We give you an injection of sedation medicine and painkillers through a small needle in the back of your hand or arm.
  6. A nurse sits by your head and monitors you for the whole procedure.
  7. When you are sleepy, we pass a flexible tube (endoscope) with a tiny camera on the end through your mouth. This tube goes into your stomach and the top part of your small intestine (the duodenum).
  8. The doctor puts a fine wire through the endoscope and into the bile ducts.
  9. The doctor injects a dye through the tube, which shows up on the X-ray.
  10. We take X-ray pictures of various parts of your biliary system.

We might take samples (biopsies) from the bile ducts using a small brush or forceps (a pair of pincers or tweezers). Sometimes, we might put in a plastic or metal tube (stent) to help drain bile or pancreatic juice. 

If we plan to remove stones from the bile or pancreatic duct, we might make a small cut (sphincterotomy) in the lower end of the duct. We can then pass through a fine tube and remove the stones. Any stones that might block the duct in future can easily pass into the small intestine.

Doctors in training

Doctors in training are likely to be present during your procedure. A consultant fully supervises and stands next to them. They only do parts of the procedure that their training has covered.


You have an ERCP with sedation or, in some cases, a general anaesthetic. We tell you if you need to have a general anaesthetic.

Before your procedure, we give you painkillers to make you as comfortable as possible. You might have short periods of discomfort or pain from some parts of the procedure. This should not last long.

We give you pain medicine in your bottom (a suppository) before the end of the procedure. This reduces the risk of pancreatitis (inflammation of the pancreas).

You might have cramps and tummy (abdominal) pain after the procedure. This is because of the air used to inflate your small intestine. You can take simple painkillers, such as paracetamol, after the ERCP.

Read more about side effects after an ERCP

Tell your doctor or nurse immediately if:

  • you have severe tummy pain after an ERCP

If you are at home, contact your GP or go to the nearest emergency department (A&E). Take your endoscopy report with you.

Resource number: 2559/VER5
Last reviewed: December 2021
Next review: December 2024

Contact us

If you have any questions or concerns about having an ERCP and you are in hospital, please speak to your nurse.

If you are at home and you have any questions, or you need to cancel or change your appointment, please contact the endoscopy unit.

Phone: 020 7188 8887, Monday to Saturday, 9am to 5pm

You can also contact:

In an emergency

Out of hours (evenings and weekends), please phone 020 7188 7188 and ask to be put through to the on-call gastroenterology registrar (through a system called RotaWatch).

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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