Endoscopic ultrasound (EUS) is used to look closely at certain abdominal organs which can be seen in detail from the oesophagus (swallowing tube), stomach and duodenum (the top part of the small bowel). It not only provides good pictures but allows the doctors to take samples if needed.
The doctor will steer a thin flexible tube containing a miniature camera (endoscope) through your mouth and down the oesophagus, through your stomach and into the duodenum. This endoscope has a small ultrasound scanner on the end of it.
Sometimes samples may be taken using equipment passed down the endoscope. It is also possible to perform more complex procedures using EUS. Any specific procedures we plan to do at the time of the EUS will be discussed with you in advance.
Before you agree to this procedure, you will have the opportunity to speak with the staff doing the procedure so that you are aware of the reason the procedure is being done, the alternatives and the problems that can occur.
For most people, EUS is a simple and safe procedure. Unusual complications do sometimes occur and include damage or perforation (a hole) in the wall of the oesophagus, stomach or duodenum, allergy to sedative medication, bleeding, chest infection and damage to teeth. Although we have selected EUS as the best procedure to diagnose your symptoms, no procedure is perfect. There is a small risk that we might miss a lesion or other important findings during your procedure.
If biopsies of the pancreas are taken, there is a small risk of developing pancreatitis (inflammation of the pancreas) but this is rarely severe.
Since X-rays are sometimes taken during the procedure, please notify the doctor or nurse beforehand if there is any possibility you may be pregnant.
Please let us know as soon as possible about all the medications that you take, in particular blood thinners (e.g. clopidogrel, warfarin, or heparin), which may need to be stopped or adjusted up to one week before the procedure. There is usually no need to stop aspirin prior to EUS.
Please continue to take any other medication (including laxatives).
You should not eat anything for six hours before the appointment.
You may drink water only for up to four hours prior to the procedure (your usual prescription medicines can be taken with a sip of water).
If you are a diabetic and take insulin, it is important that you continue taking your insulin but it is suggested that you reduce your dose on the day and night before the procedure. If you are concerned, then contact your local diabetes nurse for advice. To keep you safe for the procedure, please check your blood sugars every three to four hours from the time you stop eating.
If you are taking tablets for your diabetes, please do not take them on the day of the procedure until after the procedure has been done.
Please bring your diabetic tablets or insulin to the hospital with you.
Please tell the doctor or nurse if you have had any previous endoscopy examinations, if you have any allergies or have had bad reactions to medications, iodine or medical dyes. You may need to put on a hospital gown and remove contact lenses if you wear them. If you wear glasses or have dentures, you will be asked to remove them before the procedure.
Sometimes, due to emergencies and other unforeseen circumstances, your appointment may be delayed or postponed. We will try our best to see you on time but please understand that delays can occur and we ask for your patience in these circumstances.
By law we must ask you to sign a consent form. This confirms that you will agree to have the procedure and understand what it involves. The doctor will explain the risks, benefits and alternatives before he or she asks you to sign the consent form. This is an opportunity for you to ask the doctor any questions you may have regarding the procedure.
Local anaesthetic may be sprayed to numb your throat, and you may be given medications by injection through a vein to make you sleepy and relaxed. Occasionally the procedure is performed with a full general anaesthetic but this is usually not necessary. You will be asked to lie on your left side. A guard will be placed in your mouth to protect your teeth.
While in this position, the doctor will pass the endoscope through your mouth and down your throat. The endoscope will not interfere with your breathing. You may experience some discomfort during the procedure. The examination usually takes about half an hour, but complicated treatment procedures may take up to an hour.
Some abdominal discomfort and bloating is common. This usually settles after a few hours. Your throat may feel numb and slightly sore, and because of the local anaesthetic and sedation you should not attempt to eat or drink anything for at least one hour after the procedure.
Drinking fluids should be possible after one hour and a soft diet (e.g. scrambled eggs, rice with plenty of liquid, mashed potato, pureed food or ice-cream) later that day. Tolerating solid food might take a day or two.
If you are due to go home after the procedure, a member of the medical team will review you before you leave.
You must be accompanied home by a responsible adult if you are going home on the same day as your EUS. They must stay with you 24 hours after your procedure.
We would advise you not to use public transport, particularly if you need to stand on the train or bus.
Do not drive yourself. Please arrange for someone to take you home in a car or taxi (public transport is not recommended).
Do not drink alcohol for 24 hours after sedation or make important decisions or sign important documents.
Do not drive a car or operate heavy machinery and / or appliances, such as cookers and kettles, for 24 hours after sedation is given.
EUS is a safe procedure. However, the following symptoms might suggest a complication:
- Severe persistent pain
- Light-headedness, or fainting
- Shivering or fever
- Vomiting of blood
- Passing of blood or black tar-like stools
- Feeling generally very unwell.
If you have any problems, please contact the Hepatobiliary Team Pathway Co-ordinator or Specialist Nurse in the first instance
If you have a problem outside of working hours which cannot wait until the next day, please contact the hospital switchboard and ask to be put through to the on call Gastroenterology Registrar. In an emergency, please visit your nearest Accident and Emergency Department.
Contact information is provided below.
Endoscopy Booking Team (Monday to Friday 09:00-17:00)
Direct line: 020 3456 7022
Switchboard: 0845 155 5000 / 020 3456 7890 ext. 67022
E-mail: uclh.
Endoscopy Recovery (Monday to Saturday 09:00-17:00)
Direct line: 020 3447 3282
Switchboard: 0845 155 5000 / 020 3456 7890 ext. 73282
Hepatobiliary Pathway Co-ordinator (Monday to Friday 09:30-17:30)
Direct line: 020 3447 9229
Switchboard: 0845 155 5000 / 020 3456 7890 ext. 79229
Hepatobiliary Clinical Nurse Specialist (Monday to Friday 09:00-17:00)
Mobile: 07967 760 146
On-call Gastroenterology Registrar (out of hours emergencies only)
Switchboard: 0845 155 5000 / 020 3456 7890
Address: Endoscopy Unit, University College Hospital, 2nd Floor Podium, 235 Euston Road, London, NW1 2BU
Page last updated: 11 June 2025
Review due: 01 June 2027