Patient guide · Gastroenterology · 6 min read
Endoscopic ultrasound (EUS), combines endoscopy with ultrasound for pancreas, bile duct and GI wall imaging plus targeted biopsy.
Endoscopic ultrasound (EUS) combines a flexible endoscope with an ultrasound probe to image the GI wall, pancreas, bile duct and adjacent structures — and to biopsy them using EUS-guided fine-needle aspiration (FNA) or biopsy (FNB).
Reviewed by Pulse Atlas Editorial Board () · Published 2026-07-30 · Next review 2027-07-30
Key facts about EUS
- 01
Definition
Endoscopy combined with a high-frequency ultrasound probe, with FNA / FNB biopsy capability at the same sitting.
- 02
Pancreatic mass biopsy
The most accurate route to tissue diagnosis for solid pancreatic and peri-pancreatic lesions.
- 03
GI-wall layered imaging
Resolves the five layers of the GI wall — the reference test for early-tumour T-staging.
- 04
Biliary and pancreatic ducts
Maps common bile duct and pancreatic duct anatomy without ionising radiation.
- 05
Nodes: mediastinum and abdomen
Characterises and samples mediastinal and coeliac / peri-portal lymphadenopathy.
- 06
Day-case, conscious sedation
Performed as a day-case procedure with conscious sedation — home the same day.
How EUS is done
Preparation and the procedure, step by step.
From consultant referral to same-day discharge — what actually happens on the day of your EUS.
- 01
Before
Gastroenterology consultation
Consultant review of your symptoms, imaging and bloods to confirm EUS is the right next step.
- 02
Before
Fast for 6 hours
Nil by mouth for six hours before the procedure. Clear fluids up to two hours before, unless told otherwise.
- 03
On the day
Conscious sedation
IV sedation and throat spray in the endoscopy suite — you stay breathing and can respond, but won’t remember much.
- 04
On the day
EUS scope inserted trans-orally
The scope passes through the mouth into the oesophagus, stomach and duodenum, similar to a standard gastroscopy.
- 05
On the day
Radial or linear US imaging
Radial for staging views; linear for real-time biopsy guidance of masses, nodes and cysts.
- 06
On the day
FNA / FNB where indicated
A fine needle is passed through the scope under ultrasound guidance to sample tissue in the same sitting.
- 07
After
Recovery and same-day discharge
Around an hour in recovery. You’ll need someone to take you home — no driving or work for 24 hours.
What it shows
When EUS is the right test.
EUS answers specific questions about the pancreas, bile duct and GI wall that CT and MRI often can’t — and it can biopsy in the same sitting.
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Pancreatic mass and cysts
Characterises solid and cystic pancreatic lesions and enables same-sitting FNA / FNB.
-
Common bile duct stones
Detects small choledocholithiasis missed by CT and MRCP, guiding onward ERCP.
-
Ampullary tumours
Direct visualisation and biopsy of ampullary lesions with local T-staging.
-
Submucosal GI lesions (GIST)
Identifies the layer of origin of submucosal lesions and enables targeted sampling.
-
Rectal cancer T-staging
Layered wall imaging distinguishes T1–T2 disease to guide local excision decisions.
-
Mediastinal / abdominal lymphadenopathy
Characterises and samples nodes not safely reached by percutaneous biopsy.
-
Small pancreatic neuroendocrine tumours
Detects sub-centimetre pancreatic NETs below the resolution of standard cross-sectional imaging.
-
Red flag: pancreatic mass — 2-week-wait oncology referral
A newly identified solid pancreatic mass triggers an urgent suspected-cancer referral.
Next steps
What happens after your EUS.
Depending on the findings, EUS opens onto one of several MDT-led pathways — surgical, oncological, endoscopic or palliative.
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Pancreatic MDT
Discussion at a specialist HPB multidisciplinary team meeting to agree resectability and pathway.
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Whipple / distal pancreatectomy
Curative resection for anatomically resectable pancreatic head or body / tail tumours.
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Neoadjuvant chemotherapy
Systemic therapy before surgery for borderline-resectable or locally advanced disease.
-
ERCP for CBD stones
Therapeutic endoscopy to clear common bile duct stones identified on EUS.
-
EUS-guided drainage of pancreatic collections
Trans-gastric stent drainage of walled-off pancreatic necrosis or pseudocysts.
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EUS-guided coeliac plexus block
Targeted analgesia for chronic pancreatitis or pancreatic-cancer pain.
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Bariatric-planning EUS
Pre-operative assessment of the pancreas and biliary tree before bariatric surgery.
-
Structured MDT follow-up
Interval imaging and clinic review with the HPB or upper-GI team, per NG85.
Red flags and safety
Findings and complications that need urgent action.
Serious findings on EUS — and the rare procedural complications — that trigger urgent referral or same-day medical review.
-
Pancreatic mass
Solid pancreatic lesion — urgent 2-week-wait suspected-cancer referral, MDT discussion.
-
Cystic pancreatic lesion — worrisome features
Mural nodule, thickened wall, dilated main duct or size > 3 cm needs specialist follow-up.
-
Post-EUS pancreatitis
Uncommon but recognised complication after pancreatic FNA — acute abdominal pain and raised lipase.
-
Perforation (rare)
Rare oesophageal, duodenal or rectal perforation — requires urgent surgical review.
-
Bleeding post-FNA
Uncommon; monitored in recovery and managed endoscopically or with transfusion if needed.
-
Ampullary cancer
Suspicious ampullary lesion — biopsy plus HPB / upper-GI MDT referral.
-
Suspected mesothelioma via EUS
Mediastinal or pleural sampling suggestive of mesothelioma — thoracic MDT pathway.
-
IgG4 disease
Autoimmune pancreatitis pattern on EUS with raised IgG4 — rheumatology / HPB input.
-
Rectal cancer with T4 features
Full-thickness wall involvement or adjacent-organ invasion — urgent colorectal MDT.
Frequently asked
Everything patients ask about endoscopic ultrasound.
What EUS is, why it’s used for the pancreas, how it differs from gastroscopy, sedation, risks and results.
-
What is endoscopic ultrasound (EUS)?
EUS combines a flexible endoscope with a high-frequency ultrasound probe at its tip. The scope is passed through the mouth (or, for lower-GI work, through the rectum) so the ultrasound sits millimetres away from the pancreas, bile duct, GI wall and adjacent lymph nodes — giving far higher resolution than external ultrasound or CT.
-
Why is EUS used for pancreatic masses?
It is the most sensitive imaging test for small pancreatic lesions and it allows same-sitting fine-needle aspiration (FNA) or fine-needle biopsy (FNB) under real-time ultrasound guidance — the accepted route to tissue diagnosis for solid pancreatic tumours per NICE NG85.
-
How is EUS different from a standard gastroscopy?
The scope looks similar and is passed the same way, but the EUS scope carries an ultrasound transducer at the tip. That lets the operator see through the GI wall into the pancreas, bile duct, mediastinum and adjacent structures, and sample them with a needle.
-
Is EUS painful?
No. It is performed with conscious sedation and throat spray. Most patients remember very little of the procedure. Some throat discomfort and mild bloating are normal afterwards.
-
What are the risks of EUS with FNA?
Serious complications are uncommon. Recognised risks include post-EUS pancreatitis (after pancreatic FNA), bleeding, infection and — rarely — perforation of the oesophagus, duodenum or rectum. Your consultant will discuss these before consent.
-
How soon will I get results?
The endoscopic findings are usually discussed with you immediately after the procedure. Biopsy and cytology results typically take 5–10 working days and are reviewed at the HPB or upper-GI MDT before your follow-up.
Sources
Guidelines and references.
-
Reference 01
British Society of Gastroenterology. Endoscopic ultrasound guidance. -
Reference 02
European Society of Gastrointestinal Endoscopy. EUS clinical guidelines. -
Reference 03
American Society for Gastrointestinal Endoscopy. Standards of practice for EUS. -
Reference 04
NICE. Pancreatic cancer in adults: diagnosis and management (NG85).
Reviewed by Pulse Atlas Editorial Board (). Last updated 2026-07-30. Next planned review 2027-07-30.
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In practice, in London
The London pathway for endoscopic ultrasound scan
With endoscopic ultrasound scan, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. On the NHS, endoscopic ultrasound scan typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to — and it’s the single most common reason people call us in the first place.
The mechanics are straightforward: a consultant appointment, any tests done at a nearby CQC-registered site, and a written report back within a few days. London’s density of private diagnostics — Marylebone, the City, Chelsea, Canary Wharf — means most patients can find something that fits around work without a cross-town trek. For endoscopic ultrasound scan specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
Where a good concierge earns its keep is in the matching. There are dozens of consultants in London who see endoscopic ultrasound scan — but not all of them are the right fit for every case. We narrow it down based on subspecialty, insurer coverage, the specific question being asked, and whether continuity into treatment matters. The right first appointment saves you from repeating yourself later.